A search for Supersymmetry involving the pair production of gluinos decaying via third-generation squarks to the lightest neutralino is reported. It uses an LHC proton--proton dataset at a center-of-mass energy $\sqrt{s} = 13$ TeV with an integrated luminosity of 3.2 fb$^{-1}$ collected with the ATLAS detector in 2015. The signal is searched for in events containing several energetic jets, of which at least three must be identified as $b$-jets, large missing transverse momentum and, potentially, isolated electrons or muons. Large-radius jets with a high mass are also used to identify highly boosted top quarks. No excess is found above the predicted background. For neutralino masses below approximately 700 GeV, gluino masses of less than 1.78 TeV and 1.76 TeV are excluded at the 95% CL in simplified models of the pair production of gluinos decaying via sbottom and stop, respectively. These results significantly extend the exclusion limits obtained with the $\sqrt{s} = 8$ TeV dataset.
Distribution of missing transverse energy for SR-Gbb-B.
Distribution of missing transverse energy for SR-Gtt-0L-C.
Distribution of missing transverse energy for SR-Gtt-1L-A.
An inclusive search for a new-physics signature of lepton-jet resonances has been performed by the ATLAS experiment. Scalar leptoquarks, pair-produced in $pp$ collisions at $\sqrt{s}$ = 13 TeV at the Large Hadron Collider, have been considered. An integrated luminosity of 3.2 fb$^{-1}$, corresponding to the full 2015 dataset was used. First (second) generation leptoquarks were sought in events with two electrons (muons) and two or more jets. The observed event yield in each channel is consistent with Standard Model background expectations. The observed (expected) lower limits on the leptoquark mass at 95% confidence level are 1100 GeV and 1050 GeV (1160 GeV and 1040 GeV) for first and second generation leptoquarks, respectively, assuming a branching ratio into a charged lepton and a quark of 100%. Upper limits on the aforementioned branching ratio are also given as a function of leptoquark mass. Compared with the results of earlier ATLAS searches, the sensitivity is increased for leptoquark masses above 860 GeV, and the observed exclusion limits confirm and extend the published results.
Normalisation factors for the main backgrounds obtained from the combined fit in each of the channels. The total uncertainty is given.
Search for the first generation leptoquarks (LQs). Event yields in the Z control region (CR), ttbar CR and in the signal region (SR). Each CR is treated as one bin in the profile likelihood fit. The SR is split to 7 bins according to $m_{\text{LQ}}^{\text{min}}$ for the fit. The table below shows the total number of events in each CR. For the SR, it shows the number of events per 100 GeV as a function of $m_{\text{LQ}}^{\text{min}}$. The background expectations are scaled by a scale factor extracted from the fit. However, the uncertainties shown are the pre-fit ones. The data event yield uncertainty is statistical (gaussian). The background uncertainty consists of all the experimental and theoretical components summed in quadrature. The uncertainty of the fit-extracted background scale factor is also added in quadrature.
Search for the second generation leptoquarks (LQs). Event yields in the Z control region (CR), ttbar CR and in the signal region (SR). Each CR is treated as one bin in the profile likelihood fit. The SR is split to 7 bins according to $m_{\text{LQ}}^{\text{min}}$ for the fit. The table below shows the total number of events in each CR. For the SR, it shows the number of events per 100 GeV as a function of $m_{\text{LQ}}^{\text{min}}$. The background expectations are scaled by a scale factor extracted from the fit. However, the uncertainties shown are the pre-fit ones. The data event yield uncertainty is statistical (gaussian). The background uncertainty consists of all the experimental and theoretical components summed in quadrature. The uncertainty of the fit-extracted background scale factor is also added in quadrature.
Measurements of the $W^{\pm} \rightarrow \ell^{\pm} \nu$ and $Z \rightarrow \ell^+ \ell^-$ production cross sections (where $\ell^{\pm}=e^{\pm},\mu^{\pm}$) in proton-proton collisions at $\sqrt{s}=13$ TeV are presented using data recorded by the ATLAS experiment at the Large Hadron Collider, corresponding to a total integrated luminosity of 81 pb$^{-1}$ The total inclusive $W^{\pm}$-boson production cross sections times the single-lepton-flavour branching ratios are $\sigma_{W^+}^{tot}= 11.83 \pm 0.02 (stat) \pm 0.32 (sys) \pm 0.25 (lumi)$ nb and $\sigma_{W^-}^{tot} = 8.79 \pm 0.02 (stat) \pm 0.24 (sys) \pm 0.18 (lumi)$ nb for $W^+$ and $W^-$, respectively. The total inclusive $Z$-boson production cross section times leptonic branching ratio, within the invariant mass window $66 < m_{\ell\ell} < 116$ GeV, is $\sigma_{Z}^{tot} = 1.981 \pm 0.007 (stat) \pm 0.038 (sys) \pm 0.042 (lumi)$ nb. The $W^+$, $W^-$, and $Z$-boson production cross sections and cross-section ratios within a fiducial region defined by the detector acceptance are also measured. The cross-section ratios benefit from significant cancellation of experimental uncertainties, resulting in $\sigma_{W^+}^{fid}/\sigma_{W^-}^{fid} = 1.295 \pm 0.003 (stat) \pm 0.010 (sys)$ and $\sigma_{W^{\pm}}^{fid}/\sigma_{Z}^{fid} = 10.31 \pm 0.04 (stat) \pm 0.20 (sys)$. Theoretical predictions, based on calculations accurate to next-to-next-to-leading order for quantum chromodynamics and to next-to-leading order for electroweak processes and which employ different parton distribution function sets, are compared to these measurements.
Measured fiducial cross section times leptonic branching ratio for W+ production in the W+ -> e+ nu final state.
Measured fiducial cross section times leptonic branching ratio for W- production in the W- -> e- nubar final state.
Measured fiducial cross section times leptonic branching ratio for Z/gamma* production in the Z/gamma* -> e+e- final state.
The results of a search for gluinos in final states with an isolated electron or muon, multiple jets and large missing transverse momentum using proton--proton collision data at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV are presented. The dataset used was recorded in 2015 by the ATLAS experiment at the Large Hadron Collider and corresponds to an integrated luminosity of 3.2 fb$^{-1}$. Six signal selections are defined that best exploit the signal characteristics. The data agree with the Standard Model background expectation in all six signal selections, and the largest deviation is a 2.1 standard deviation excess. The results are interpreted in a simplified model where pair-produced gluinos decay via the lightest chargino to the lightest neutralino. In this model, gluinos are excluded up to masses of approximately 1.6 TeV depending on the mass spectrum of the simplified model, thus surpassing the limits of previous searches.
The distribution of the missing transverse momentum is shown in hard-lepton 6-jet ttbar control regions after normalising the ttbar and W+jets background processes in the simultaneous fit.
The distribution of the missing transverse momentum is shown in hard-lepton 6-jet W+jets control regions after normalising the ttbar and W+jets background processes in the simultaneous fit.
The distribution of the missing transverse momentum is shown in soft-lepton 2-jet ttbar control regions after normalising the ttbar and W+jets background processes in the simultaneous fit.
This paper describes a measurement of the inclusive top quark pair production cross-section ($\sigma_{t\bar{t}}$) with a data sample of 3.2 fb$^{-1}$ of proton--proton collisions at a centre-of-mass energy of $\sqrt{s}$=13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron--muon pair in the final state. Jets containing $b$-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two $b$-tagged jets are counted and used to determine simultaneously $\sigma_{t\bar{t}}$ and the efficiency to reconstruct and $b$-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: $\sigma_{t\bar{t}}$= 818 $\pm$ 8 (stat) $\pm$ 27 (syst) $\pm$ 19 (lumi) $\pm$ 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented.
Measured cross-section for $t\bar{t}$ events using $e\mu$ events with b-tagged jets in pp collisions at $\sqrt{s}$=13 TeV.
Measured fiducial cross-section for $t\bar{t}$ events producing an $e\mu$ pair, each lepton originating directly from t $\rightarrow$ W $\rightarrow$ l or via a leptonic $\tau$ decay t $\rightarrow$ W $\rightarrow$ $\tau$ $\rightarrow$ l and satisfying p$_{\mathrm{T}} > $ 25 GeV and $|\eta| <$ 2.5.
This Letter presents a measurement of the inelastic proton-proton cross section using 60 $\mu$b$^{-1}$ of $pp$ collisions at a center-of-mass energy $\sqrt{s}$ of $13$ TeV with the ATLAS detector at the LHC. Inelastic interactions are selected using rings of plastic scintillators in the forward region ($2.07<|\eta|<3.86$) of the detector. A cross section of $68.1\pm 1.4$ mb is measured in the fiducial region $\xi=M_X^2/s>10^{-6}$, where $M_X$ is the larger invariant mass of the two hadronic systems separated by the largest rapidity gap in the event. In this $\xi$ range the scintillators are highly efficient. For diffractive events this corresponds to cases where at least one proton dissociates to a system with $M_X>13$ GeV. The measured cross section is compared with a range of theoretical predictions. When extrapolated to the full phase space, a cross-section of $78.1 \pm 2.9$ mb is measured, consistent with the inelastic cross section increasing with center-of-mass energy.
The measured and extrapolated inelastic cross section. The statistical uncertainty is negligible and is therefore displayed as zero. The first systematic uncertainty is the experimental systematic uncertainty apart from the luminosity, the second is the luminosity uncertainty, and the third is the extrapolation uncertainty.
The result of a search for pair production of the supersymmetric partner of the Standard Model bottom quark ($\tilde{b}_1$) is reported. The search uses 3.2 fb$^{-1}$ of $pp$ collisions at $\sqrt{s}=$13 TeV collected by the ATLAS experiment at the Large Hadron Collider in 2015. Bottom squarks are searched for in events containing large missing transverse momentum and exactly two jets identified as originating from $b$-quarks. No excess above the expected Standard Model background yield is observed. Exclusion limits at 95% confidence level on the mass of the bottom squark are derived in phenomenological supersymmetric $R$-parity-conserving models in which the $\tilde{b}_1$ is the lightest squark and is assumed to decay exclusively via $\tilde{b}_1 \rightarrow b \tilde{\chi}_1^0$, where $\tilde{\chi}_1^0$ is the lightest neutralino. The limits significantly extend previous results; bottom squark masses up to 800 (840) GeV are excluded for the $\tilde{\chi}_1^0$ mass below 360 (100) GeV whilst differences in mass above 100 GeV between the $\tilde{b}_1$ and the $\tilde{\chi}_1^0$ are excluded up to a $\tilde{b}_1$ mass of 500 GeV.
Expected exclusion limit at 95% CL in the $m(\tilde b_1)$-$m(\tilde\chi^0_1)$ plane for the sbottom pair production scenario.
Observed exclusion limit at 95% CL in the $m(\tilde b_1)$-$m(\tilde\chi^0_1)$ plane for the sbottom pair production scenario.
Signal region (SR) providing the best expected sensitivity in the $m(\tilde b_1)$-$m(\tilde\chi^0_1)$ plane.
The results of a search for the stop, the supersymmetric partner of the top quark, in final states with one isolated electron or muon, jets, and missing transverse momentum are reported. The search uses the 2015 LHC $pp$ collision data at a center-of-mass energy of $\sqrt{s}=13$ TeV recorded by the ATLAS detector and corresponding to an integrated luminosity of 3.2 fb${}^{-1}$. The analysis targets two types of signal models: gluino-mediated pair production of stops with a nearly mass-degenerate stop and neutralino; and direct pair production of stops, decaying to the top quark and the lightest neutralino. The experimental signature in both signal scenarios is similar to that of a top quark pair produced in association with large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits on gluino and stop masses are set at 95% confidence level. The results extend the LHC Run-1 exclusion limit on the gluino mass up to 1460 GeV in the gluino-mediated scenario in the high gluino and low stop mass region, and add an excluded stop mass region from 745 to 780 GeV for the direct stop model with a massless lightest neutralino. The results are also reinterpreted to set exclusion limits in a model of vector-like top quarks.
Comparison of data with estimated backgrounds in the $am_\text{T2}$ distribution with the STCR1 event selection except for the requirement on $am_\text{T2}$. The predicted backgrounds are scaled with normalization factors. The uncertainty band includes statistical and all experimental systematic uncertainties. The last bin includes overflow.
Comparison of data with estimated backgrounds in the $b$-tagged jet multiplicity with the STCR1 event selection except for the requirement on the $b$-tagged jet multiplicity. Furthermore, the $\Delta R(b_1,b_2)$ requirement is dropped. The predicted backgrounds are scaled with normalization factors. The uncertainty band includes statistical and all experimental systematic uncertainties. The last bin includes overflow.
Comparison of data with estimated backgrounds in the $\Delta R(b_1,b_2)$ distribution with the STCR1 event selection except for the requirement on $\Delta R(b_1,b_2)$. The predicted backgrounds are scaled with normalization factors. The uncertainty band includes statistical and all experimental systematic uncertainties. The last bin includes overflow.
A search for strongly produced supersymmetric particles is conducted using signatures involving multiple energetic jets and either two isolated leptons ($e$ or $\mu$) with the same electric charge or at least three isolated leptons. The search also utilises $b$-tagged jets, missing transverse momentum and other observables to extend its sensitivity. The analysis uses a data sample of proton-proton collisions at $\sqrt{s}=13$ TeV recorded with the ATLAS detector at the Large Hadron Collider in 2015 corresponding to a total integrated luminosity of 3.2 fb$^{-1}$. No significant excess over the Standard Model expectation is observed. The results are interpreted in several simplified supersymmetric models and extend the exclusion limits from previous searches. In the context of exclusive production and simplified decay modes, gluino masses are excluded at 95% confidence level up to 1.1-1.3 TeV for light neutralinos (depending on the decay channel), and bottom squark masses are also excluded up to 540 GeV. In the former scenarios, neutralino masses are also excluded up to 550-850 GeV for gluino masses around 1 TeV.
Missing transverse momentum distribution after SR0b3j selection, beside the $E_\mathrm{T}^\mathrm{miss}$ requirement. The results in the signal region correspond to the last inclusive bin. The systematic uncertainties include theory uncertainties for the backgrounds with prompt SS/3L and the full systematic uncertainties for data-driven backgrounds. For illustration the distribution for a benchmark SUSY scenario ($pp\to \tilde g\tilde g$, $\tilde g\to qq(\tilde\ell\ell/\tilde\nu\nu)$, $m_{\tilde g}=1.3$ TeV, $m_{\tilde\chi_1^0}=0.5$ TeV) is also shown.
Missing transverse momentum distribution after SR0b5j selection, beside the $E_\mathrm{T}^\mathrm{miss}$ requirement. The results in the signal region correspond to the last inclusive bin. The systematic uncertainties include theory uncertainties for the backgrounds with prompt SS/3L and the full systematic uncertainties for data-driven backgrounds. For illustration the distribution for a benchmark SUSY scenario ($pp\to \tilde g\tilde g$, $\tilde g\to qqWZ\tilde\chi_1^0$, $m_{\tilde g}=1.1$ TeV, $m_{\tilde\chi_1^0}=0.4$ TeV) is also shown.
Missing transverse momentum distribution after SR1b selection, beside the $E_\mathrm{T}^\mathrm{miss}$ requirement. The results in the signal region correspond to the last inclusive bin. The systematic uncertainties include theory uncertainties for the backgrounds with prompt SS/3L and the full systematic uncertainties for data-driven backgrounds. For illustration the distribution for a benchmark SUSY scenario ($pp\to \tilde b_1\tilde b_1^*$, $\tilde b_1\to tW\tilde\chi_1^0$, $m_{\tilde b_1}=600$ GeV, $m_{\tilde\chi_1^0}=50$ GeV) is also shown.
Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum with the ATLAS experiment at the Large Hadron Collider are reported. The data were collected in proton--proton collisions at a centre-of-mass energy of 13 TeV and correspond to an integrated luminosity of 3.2 $\rm fb^{-1}$. The observed data are in agreement with the Standard Model expectations. Exclusion limits are presented in models of new phenomena including pair production of dark matter candidates or large extra spatial dimensions. In a simplified model of dark matter and an axial-vector mediator, the search excludes mediator masses of up to 710 GeV for dark matter candidate masses up to 150 GeV. In an effective theory of dark matter production, values of the suppression scale $M_*$ up to 570 GeV are excluded and the effect of truncation for various coupling values is reported. For the ADD large extra spatial dimension model the search places more stringent limits than earlier searches in the same event topology, excluding $M_{\rm D}$ up to about 2.3 (2.8) TeV for two (six) additional spatial dimensions; the limits are reduced by 20--40% depending on the number of additional spatial dimensions when applying a truncation procedure.
Distribution of missing transverse momentum, reconstructed treating muons as non-interacting particles, in the data and for the background in the 1muCR. The total background expectation is normalized to the post-fit result. Overflows are included in the final bin. The errors include both statistical and systematic uncertainties determined by a bin-by-bin fit.
Distribution of missing transverse momentum, reconstructed treating muons as non-interacting particles, in the data and for the background in the 2muCR. The total background expectation is normalized to the post-fit result. Overflows are included in the final bin. The errors include both statistical and systematic uncertainties determined by a bin-by-bin fit.
Distribution of missing transverse momentum, reconstructed treating electrons as non-interacting particles, in the data and for the background in the 2eleCR. The total background expectation is normalized to the post-fit result. Overflows are included in the final bin. The errors include both statistical and systematic uncertainties determined by a bin-by-bin fit.
A search for heavy long-lived charged $R$-hadrons is reported using a data sample corresponding to 3.2$^{-1}$ of proton--proton collisions at $\sqrt{s} = 13$ TeV collected by the ATLAS experiment at the Large Hadron Collider at CERN. The search is based on observables related to large ionisation losses and slow propagation velocities, which are signatures of heavy charged particles travelling significantly slower than the speed of light. No significant deviations from the expected background are observed. Upper limits at 95% confidence level are provided on the production cross section of long-lived $R$-hadrons in the mass range from 600 GeV to 2000 GeV and gluino, bottom and top squark masses are excluded up to 1580 GeV, 805 GeV and 890 GeV, respectively.
Distributions of beta for data and simulation after a Zmumu selection. The values given for the mean and width are taken from Gaussian functions matched to data and simulation.
Data (black dots) and background estimates (red solid line) for m_beta for the gluino R-hadron search (1000 GeV). The green shaded band illustrates the statistical uncertainty of the background estimate. The blue dashed lines illustrate the expected signal (on top of background) for the given R-hadron mass hypothesis. The black dashed vertical lines at 500 GeV show the mass selection and the last bin includes all entries/masses above.
Data (black dots) and background estimates (red solid line) for m_betagamma for the gluino R-hadron search (1000 GeV). The green shaded band illustrates the statistical uncertainty of the background estimate. The blue dashed lines illustrate the expected signal (on top of background) for the given R-hadron mass hypothesis. The black dashed vertical lines at 500 GeV show the mass selection and the last bin includes all entries/masses above.
This paper presents a search for massive charged long-lived particles produced in pp collisions at $\sqrt{s}=$ 13 TeV at the LHC using the ATLAS experiment. The dataset used corresponds to an integrated luminosity of 3.2 fb$^{-1}$. Many extensions of the Standard Model predict the existence of massive charged long-lived particles, such as $R$-hadrons. These massive particles are expected to be produced with a velocity significantly below the speed of light, and therefore to have a specific ionization higher than any Standard Model particle of unit charge at high momenta. The Pixel subsystem of the ATLAS detector is used to measure the ionization energy loss of reconstructed charged particles and to search for such highly ionizing particles. The search presented here has much greater sensitivity than a similar search performed using the ATLAS detector in the $\sqrt{s}=$ 8 TeV dataset, thanks to the increase in expected signal cross-section due to the higher center-of-mass energy of collisions, to an upgraded detector with a new silicon layer close to the interaction point, and to analysis improvements. No significant deviation from Standard Model background expectations is observed, and lifetime-dependent upper limits on $R$-hadron production cross-sections and masses are set. Gluino $R$-hadrons with lifetimes above 0.4 ns and decaying to $q\bar{q}$ plus a 100 GeV neutralino are excluded at the 95% confidence level, with lower mass limit ranging between 740 GeV and 1590 GeV. In the case of stable $R$-hadrons the lower mass limit at the 95% confidence level is 1570 GeV.
Mass distribution for data and expected background for stable particle searches. Also shown are two examples for signals as expected for gluino R-hadrons in the explored mass range. The uncertainty on the background estimation includes both the statistical and systematic uncertainties.
Mass distribution for data and expected background for metastable particle searches. Also shown are two examples for signals as expected for gluino R-hadrons in the explored mass range. The uncertainty on the background estimation includes both the statistical and systematic uncertainties.
Cross-section as a function of mass for gluino R-hadrons with lifetime tau=10 ns, decaying to qanti-q plus a light neutralino of mass=100 GeV. The central value of the observed and expected 95% upper limit on excluded cross-section is given. The 1 sigma band on the expected UL is given as an uncertainty.
A measurement of the four-lepton invariant mass spectrum is made with the ATLAS detector, using an integrated luminosity of 36.1 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}$ = 13 TeV delivered by the Large Hadron Collider. The differential cross-section is measured for events containing two same-flavour opposite-sign lepton pairs. It exhibits a rich structure, with different mass regions dominated in the Standard Model by single $Z$ boson production, Higgs boson production, and $Z$ boson pair production, and non-negligible interference effects at high invariant masses. The measurement is compared with state-of-the-art Standard Model calculations, which are found to be consistent with the data. These calculations are used to interpret the data in terms of $gg\rightarrow ZZ \rightarrow 4\ell$ and $Z \rightarrow 4\ell$ subprocesses, and to place constraints on a possible contribution from physics beyond the Standard Model.
Measured and expected differential cross-section $\text{d}\sigma / \text{d} m_{4l}$ as a function of $m_{4l}$
Measured and expected differential cross-section $\text{d}\sigma / \text{d} m_{4l}$ as a function of $m_{4l}$ in bin of 0$< p_{T}^{4l} <$20 GeV
Measured and expected differential cross-section $\text{d}\sigma / \text{d} m_{4l}$ as a function of $m_{4l}$ in bin of 20$< p_{T}^{4l} <$50 GeV
A search for supersymmetry in events with large missing transverse momentum, jets, and at least one hadronically decaying $\tau$-lepton is presented. Two exclusive final states with either exactly one or at least two $\tau$-leptons are considered. The analysis is based on proton-proton collisions at $\sqrt{s}$ = 13 TeV corresponding to an integrated luminosity of 36.1 fb$^{-1}$ delivered by the Large Hadron Collider and recorded by the ATLAS detector in 2015 and 2016. No significant excess is observed over the Standard Model expectation. At 95% confidence level, model-independent upper limits on the cross section are set and exclusion limits are provided for two signal scenarios: a simplified model of gluino pair production with $\tau$-rich cascade decays, and a model with gauge-mediated supersymmetry breaking (GMSB). In the simplified model, gluino masses up to 2000 GeV are excluded for low values of the mass of the lightest supersymmetric particle (LSP), while LSP masses up to 1000 GeV are excluded for gluino masses around 1400 GeV. In the GMSB model, values of the supersymmetry-breaking scale are excluded below 110 TeV for all values of $\tan\beta$ in the range $2 \leq \tan\beta \leq 60$, and below 120 TeV for $\tan\beta>30$.
1$\tau$ Compressed SR eff.
1$\tau$ Compressed SR eff.
1$\tau$ MediumMass SR eff.
This paper presents a search for dark matter, $\chi$, using events with a single top quark and an energetic $W$ boson. The analysis is based on proton-proton collision data collected with the ATLAS experiment at $\sqrt{s}=$ 13 TeV during LHC Run 2 (2015-2018), corresponding to an integrated luminosity of 139 fb$^{-1}$. The search considers final states with zero or one charged lepton (electron or muon), at least one $b$-jet and large missing transverse momentum. In addition, a result from a previous search considering two-charged-lepton final states is included in the interpretation of the results. The data are found to be in good agreement with the Standard Model predictions and the results are interpreted in terms of 95% confidence-level exclusion limits in the context of a class of dark matter models involving an extended two-Higgs-doublet sector together with a pseudoscalar mediator particle. The search is particularly sensitive to on-shell production of the charged Higgs boson state, $H^{\pm}$, arising from the two-Higgs-doublet mixing, and its semi-invisible decays via the mediator particle, $a$: $H^{\pm} \rightarrow W^\pm a (\rightarrow \chi\chi)$. Signal models with $H^{\pm}$ masses up to 1.5 TeV and $a$ masses up to 350 GeV are excluded assuming a tan$\beta$ value of 1. For masses of $a$ of 150 (250) GeV, tan$\beta$ values up to 2 are excluded for $H^{\pm}$ masses between 200 (400) GeV and 1.5 TeV. Signals with tan$\beta$ values between 20 and 30 are excluded for $H^{\pm}$ masses between 500 and 800 GeV.
<b>- - - - - - - - Overview of HEPData Record - - - - - - - -</b> <br><br> <b>Exclusion contours:</b> <ul> <li><a href="?table=highst_mamh_obs">Combined sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=highst_mamh_exp">Combined sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=highst_mhtb_lowma_obs">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=highst_mhtb_lowma_exp">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=highst_mhtb_highma_obs">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=highst_mhtb_highma_exp">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=lowst_mamh_obs">Combined sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=lowst_mamh_exp">Combined sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=lowst_mhtb_lowma_obs">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=lowst_mhtb_lowma_exp">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=lowst_mhtb_highma_obs">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=lowst_mhtb_highma_exp">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_mamh_obs">0L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_mamh_exp">0L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_mhtb_lowma_obs">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_mhtb_lowma_exp">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_mhtb_highma_obs">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_mhtb_highma_exp">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_mamh_obs">0L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_mamh_exp">0L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_mhtb_lowma_obs">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_mhtb_lowma_exp">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_mhtb_highma_obs">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_mhtb_highma_exp">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_mamh_obs">1L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_mamh_exp">1L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_mhtb_lowma_obs">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_mhtb_lowma_exp">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_mhtb_highma_obs">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_mhtb_highma_exp">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_mamh_obs">1L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=1LBoosted_lowst_mamh_exp">1L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_mhtb_lowma_obs">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=1LBoosted_lowst_mhtb_lowma_exp">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_mhtb_highma_exp">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_highst_mamh_obs">2L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=2L_highst_mamh_exp">2L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_highst_mhtb_lowma_obs">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=2L_highst_mhtb_lowma_exp">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_highst_mhtb_highma_obs">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Obs.)</a> <li><a href="?table=2L_highst_mhtb_highma_exp">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_lowst_mamh_exp">2L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_lowst_mhtb_lowma_exp">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=2L_lowst_mhtb_highma_exp">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW signals (Exp.)</a> <li><a href="?table=highst_dmtt_mamh_obs">Combined sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=highst_dmtt_mamh_exp">Combined sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=highst_dmtt_mhtb_lowma_obs">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=highst_dmtt_mhtb_lowma_exp">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=highst_dmtt_mhtb_highma_obs">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=highst_dmtt_mhtb_highma_exp">Combined sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=lowst_dmtt_mamh_obs">Combined sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=lowst_dmtt_mamh_exp">Combined sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=lowst_dmtt_mhtb_lowma_obs">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=lowst_dmtt_mhtb_lowma_exp">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=lowst_dmtt_mhtb_highma_obs">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=lowst_dmtt_mhtb_highma_exp">Combined sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mamh_obs">0L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mamh_exp">0L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mhtb_lowma_obs">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mhtb_lowma_exp">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mhtb_highma_obs">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_highst_dmtt_mhtb_highma_exp">0L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mamh_obs">0L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mamh_exp">0L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mhtb_lowma_obs">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mhtb_lowma_exp">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mhtb_highma_obs">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=0LBoosted_lowst_dmtt_mhtb_highma_exp">0L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mamh_obs">1L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mamh_exp">1L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mhtb_lowma_obs">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mhtb_lowma_exp">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mhtb_highma_obs">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_highst_dmtt_mhtb_highma_exp">1L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mamh_obs">1L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mamh_exp">1L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mhtb_lowma_obs">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mhtb_lowma_exp">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mhtb_highma_obs">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=1LBoosted_lowst_dmtt_mhtb_highma_exp">1L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_highst_dmtt_mamh_obs">2L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=2L_highst_dmtt_mamh_exp">2L channel sin$\theta$ = 0.7 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_highst_dmtt_mhtb_lowma_obs">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=2L_highst_dmtt_mhtb_lowma_exp">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_highst_dmtt_mhtb_highma_obs">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=2L_highst_dmtt_mhtb_highma_exp">2L channel sin$\theta$ = 0.7 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_lowst_dmtt_mamh_exp">2L channel sin$\theta$ = 0.35 $m_a$-$m_{H^{\pm}}$ exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_lowst_dmtt_mhtb_lowma_obs">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=2L_lowst_dmtt_mhtb_lowma_exp">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 150 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> <li><a href="?table=2L_lowst_dmtt_mhtb_highma_obs">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Obs.)</a> <li><a href="?table=2L_lowst_dmtt_mhtb_highma_exp">2L channel sin$\theta$ = 0.35 $m_{H^{\pm}}$-tan$\beta$ ($m_{a}$ = 250 GeV) exclusion contour using DMtW+DMtt signals (Exp.)</a> </ul> <b>Upper limits:</b> <ul> <li><a href="?table=mamH_xSecUpperLimit_Comb_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_Comb_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_Comb_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_Comb_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_Comb_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_Comb_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.7) cross-sections from combined (0L+1L+2L) fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_Comb_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_Comb_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_Comb_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_Comb_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_Comb_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_Comb_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.35) cross-sections from combined (0L+1L+2L) fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_0L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 0L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_0L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 0L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_0L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 0L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_0L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.7) cross-sections from 0L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_0L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.7) cross-sections from 0L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_0L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.7) cross-sections from 0L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_0L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 0L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_0L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 0L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_0L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 0L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_0L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.35) cross-sections from 0L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_0L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.35) cross-sections from 0L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_0L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.35) cross-sections from 0L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_1L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 1L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_1L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 1L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_1L_st0p7">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.7) cross-sections from 1L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_1L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.7) cross-sections from 1L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_1L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.7) cross-sections from 1L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_1L_st0p7_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.7) cross-sections from 1L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_1L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 1L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_1L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 1L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_1L_st0p35">Observed upper limit on the 2HDM+a tW+DM (sin$\theta$ = 0.35) cross-sections from 1L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mamH_xSecUpperLimit_1L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM(sin$\theta$ = 0.35) cross-sections from 1L individual fit in the $m_a$-$m_{H^{\pm}}$ plane.</a> <li><a href="?table=mHtblow_xSecUpperLimit_1L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM +tt+DM (sin$\theta$ = 0.35) cross-sections from 1L individual fit in the low $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> <li><a href="?table=mHtbhigh_xSecUpperLimit_1L_st0p35_DMtt">Observed upper limit on the 2HDM+a tW+DM + tt+DM (sin$\theta$ = 0.35) cross-sections from 1L individual fit in the high $m_a$ $m_{H^{\pm}}$-tan$\beta$ plane.</a> </ul> <b>Kinematic distributions:</b> <ul> <li><a href="?table=SR0L_mwtagged">0L region m(b1,W-tagged)</a> <li><a href="?table=SR0L_mtbmet">0L region m_{\mathrm{T}}^{\mathrm{b,E_{\mathrm{T}^{\mathrm{miss}}}}}</a> <li><a href="?table=SR0L_nwtagged">0L region N_{\mathrm{W-tagged}}</a> <li><a href="?table=SR1L_Had_mbj">1L hadronic top $m_{\mathrm{b1},\mathrm{\cancel{b1}}}$</a> <li><a href="?table=SR1L_Lep_mbj">1L leptonic top $m_{\mathrm{b1},\mathrm{\cancel{b1}}}$</a> <li><a href="?table=SR1L_Lep_nwtaggged">1L leptonic top region N_{\mathrm{W-tagged}}</a> </ul> <b>Cut flows:</b> <ul> <li><a href="?table=cutflow_SR0L">Cutflow of 4 signal points in the 0L regions.</a> <li><a href="?table=cutflow_SR1L_Had">Cutflow of 4 signal points in the 1L hadronic top regions.</a> <li><a href="?table=cutflow_SR1L_Lep">Cutflow of 4 signal points in the 1L leptonic top region.</a> </ul> <b>Acceptance and efficiencies:</b> <ul> <li> <b>highst_grid1_0L:</b> <a href="?table=highst_grid1_Acc_0L">Acceptance table of the 0L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <a href="?table=highst_grid1_Eff_0L">Efficiency table of the 0L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <li> <b>highst_grid2_0L:</b> <a href="?table=highst_grid2_Acc_0L">Acceptance table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <a href="?table=highst_grid2_Eff_0L">Efficiency table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <li> <b>highst_grid3_0L:</b> <a href="?table=highst_grid3_Acc_0L">Acceptance table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <a href="?table=highst_grid3_Eff_0L">Efficiency table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <li> <b>highst_grid1_1L:</b> <a href="?table=highst_grid1_Acc_1L">Acceptance table of the 1L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <a href="?table=highst_grid1_Eff_1L">Efficiency table of the 1L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <li> <b>highst_grid2_1L:</b> <a href="?table=highst_grid2_Acc_1L">Acceptance table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <a href="?table=highst_grid2_Eff_1L">Efficiency table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <li> <b>highst_grid3_1L:</b> <a href="?table=highst_grid3_Acc_1L">Acceptance table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <a href="?table=highst_grid3_Eff_1L">Efficiency table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.7, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <li> <b>lowst_grid1_0L:</b> <a href="?table=lowst_grid1_Acc_0L">Acceptance table of the 0L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <a href="?table=lowst_grid1_Eff_0L">Efficiency table of the 0L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <li> <b>lowst_grid2_0L:</b> <a href="?table=lowst_grid2_Acc_0L">Acceptance table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <a href="?table=lowst_grid2_Eff_0L">Efficiency table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <li> <b>lowst_grid3_0L:</b> <a href="?table=lowst_grid3_Acc_0L">Acceptance table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <a href="?table=lowst_grid3_Eff_0L">Efficiency table of the 0L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <li> <b>lowst_grid1_1L:</b> <a href="?table=lowst_grid1_Acc_1L">Acceptance table of the 1L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <a href="?table=lowst_grid1_Eff_1L">Efficiency table of the 1L SRs in the $m_a$-$m_{H^{\pm}}$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and tan$\beta$ = 1.</a> <li> <b>lowst_grid2_1L:</b> <a href="?table=lowst_grid2_Acc_1L">Acceptance table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <a href="?table=lowst_grid2_Eff_1L">Efficiency table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 150 GeV.</a> <li> <b>lowst_grid3_1L:</b> <a href="?table=lowst_grid3_Acc_1L">Acceptance table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> <a href="?table=lowst_grid3_Eff_1L">Efficiency table of the 1L SRs in the $m_{H^{\pm}}$-tan$\beta$ plane for 2HDM+a signals with sin$\theta$ = 0.35, $m_{\chi}$ = 10 GeV and $m_a$ = 250 GeV.</a> </ul> <b>Truth Code snippets</b> are available under "Resources" (purple button on the left)
The observed exclusion contour at 95% CL as a function of the $m_a$ vs. $m_{H^{\pm}}$ and assuming tan$\beta$ = 1, $m_{\mathrm{DM}} = 10 \mathrm{GeV}$, $g_{\chi} = 1$ and sin$\theta = 0.7$. Masses that are within the contours are excluded. Only signals simulating the tW+DM final states are considered in this contour.
The expected exclusion contour at 95% CL as a function of the $m_a$ vs. $m_{H^{\pm}}$ and assuming tan$\beta$ = 1, $m_{\mathrm{DM}} = 10 \mathrm{GeV}$, $g_{\chi} = 1$ and sin$\theta = 0.7$. Masses that are within the contours are excluded. Only signals simulating the tW+DM final states are considered in this contour.
This Letter presents the measurement of the fiducial and differential cross-sections of the electroweak production of a $Z \gamma$ pair in association with two jets. The analysis uses 140 fb$^{-1}$ of LHC proton-proton collision data taken at $\sqrt{s}$=13 TeV recorded by the ATLAS detector during the years 2015-2018. Events with a $Z$ boson candidate decaying into either an $e^+e^-$ or $\mu^+ \mu^-$ pair, a photon and two jets are selected. The electroweak component is extracted by requiring a large dijet invariant mass and a large rapidity gap between the two jets and is measured with an observed and expected significance well above five standard deviations. The fiducial $pp \rightarrow Z \gamma jj$ cross-section for the electroweak production is measured to be 3.6 $\pm$ 0.5 fb. The total fiducial cross-section that also includes contributions where the jets arise from strong interactions is measured to be $16.8^{+2.0}_{-1.8}$ fb. The results are consistent with the Standard Model predictions. Differential cross-sections are also measured using the same events and are compared with parton-shower Monte Carlo simulations. Good agreement is observed between data and predictions.
Post-fit mjj distributions in the mjj>500 GeV SR. The uncertainty band around the expectation includes all systematic uncertainties (including MC statistical uncertainty) and takes into account their correlations as obtained from the fit. The error bar around the data points represents the data statistical uncertainty. Events beyond the upper limit of the histogram are included in the last bin.
Post-fit mjj distributions in the mjj>500 GeV CR. The uncertainty band around the expectation includes all systematic uncertainties (including MC statistical uncertainty) and takes into account their correlations as obtained from the fit. The error bar around the data points represents the data statistical uncertainty. Events beyond the upper limit of the histogram are included in the last bin.
Post-fit mjj distributions in the mjj>150 GeV Extended SR. The uncertainty band around the expectation includes all systematic uncertainties (including MC statistical uncertainty) and takes into account their correlations as obtained from the fit. The error bar around the data points represents the data statistical uncertainty. Events beyond the upper limit of the histogram are included in the last bin.
Dijet events are studied in the proton--proton collision dataset recorded at $\sqrt{s}=$13 TeV with the ATLAS detector at the Large Hadron Collider in 2015 and 2016, corresponding to integrated luminosities of 3.5 fb$^{-1}$ and 33.5 fb$^{-1}$ respectively. Invariant mass and angular distributions are compared to background predictions and no significant deviation is observed. For resonance searches, a new method for fitting the background component of the invariant mass distribution is employed. The dataset is then used to set upper limits at a 95% confidence level on a range of new physics scenarios. Excited quarks with masses below 6.0 TeV are excluded, and limits are set on quantum black holes, heavy W' bosons, W* bosons, and a range of masses and couplings in a Z' dark matter mediator model. Model-independent limits on signals with a Gaussian shape are also set, using a new approach allowing factorization of physics and detector effects. From the angular distributions, a scale of new physics in contact interaction models is excluded for scenarios with either constructive or destructive interference. These results represent a substantial improvement over those obtained previously with lower integrated luminosity.
The number of events as a function of the dijet invariant mass, compared to background prediction from fit and corresponding uncertainties, in the region defined by |y*|<0.6
The number of events as a function of the dijet invariant mass, compared to background prediction from fit and corresponding uncertainties, in the region defined by |y*|<0.6
The number of events as a function of the dijet invariant mass, compared to background prediction from fit and corresponding uncertainties, in the region defined by |y*|<1.2 optimized for the W* search.
A combination of the searches for pair-produced vector-like partners of the top and bottom quarks in various decay channels ($T$$\rightarrow$$Zt/Wb/Ht$, $B$$\rightarrow$$Zb/Wt/Hb$) is performed using 36.1 fb$^{-1}$ of $pp$ collision data at $\sqrt{s}$ = 13 TeV with the ATLAS detector at the Large Hadron Collider. The observed data are found to be in good agreement with the Standard Model background prediction in all individual searches. Therefore, combined 95% confidence-level upper limits are set on the production cross-section for a range of vector-like quark scenarios, significantly improving upon the reach of the individual searches. Model-independent limits are set assuming the vector-like quarks decay to Standard Model particles. A singlet $T$ is excluded for masses below 1.31 TeV and a singlet $B$ is excluded for masses below 1.22 TeV. Assuming a weak isospin $(T,B)$ doublet and $|V_{Tb}| \ll |V_{tB}|$, $T$ and $B$ masses below 1.37 TeV are excluded.
Expected and observed 95% lower limits on the vector-like top quark mass as a function of the branching ratio, asumming that the vector-like quarks exclusively decay to SM particles (and third generation quarks).
Expected and observed 95% lower limits on the vector-like bottom quark mass as a function of the branching ratio, asumming that the vector-like quarks exclusively decay to SM particles (and third generation quarks).
Expected and observed 95% upper limits on the vector-like top quark pair-production signal strength (i.e. the ratio sigma_exclusion/sigma_VLQ) as a function of the branching ratio for a vector-like quark mass of 800 GeV, asumming that the vector-like quarks exclusively decay to SM particles (and third generation quarks). If interpreting these results in models with decays to non-Standard-Model particles, one must check that the additional decays will not end up in any control regions of the relevant analyses.
A search is presented for the pair production of heavy vector-like quarks, $T\bar T$ or $B\bar B$, that decay into final states with jets and no reconstructed leptons. Jets in the final state are classified using a deep neural network as arising from hadronically decaying $W/Z$ bosons, Higgs bosons, top quarks, or background. The analysis uses data from the ATLAS experiment corresponding to 36.1 fb$^{-1}$ of proton-proton collisions with a center-of-mass energy of $\sqrt{s} = 13$ TeV delivered by the Large Hadron Collider in 2015 and 2016. No significant deviation from the Standard Model expectation is observed. Results are interpreted assuming the vector-like quarks decay into a Standard Model boson and a third-generation-quark, $T\rightarrow Wb,Ht,Zt$ or $B\rightarrow Wt,Hb,Zb$, for a variety of branching ratios. At 95% confidence level, the observed (expected) lower limit on the vector-like $B$-quark mass for a weak-isospin doublet ($B, Y$) is 950 (890) GeV, and the lower limits on the masses for the pure decays $B\rightarrow Hb$ and $T\rightarrow Ht$, where these results are strongest, are 1010 (970) GeV and 1010 (1010) GeV, respectively.
Expected and observed upper limits at the 95% CL on the $T\bar T$ cross section as a function of $T$ mass under the assumption BR($T\to Ht$)=1.
Expected and observed upper limits at the 95% CL on the $B\bar B$ cross section as a function of $B$ mass under the assumption BR($B\to Hb$)=1.
Expected and observed upper limits at the 95% CL on the $B\bar B$ cross section as a function of $B$ mass under the assumption of a weak-isospin doublet.
A search for resonant and non-resonant pair production of Higgs bosons in the $b\bar{b}\tau^+\tau^-$ final state is presented. The search uses 36.1 fb$^{-1}$ of $pp$ collision data with $\sqrt{s}= 13$ TeV recorded by the ATLAS experiment at the LHC in 2015 and 2016. The semileptonic and fully hadronic decays of the $\tau$-lepton pair are considered. No significant excess above the expected background is observed in the data. The cross-section times branching ratio for non-resonant Higgs boson pair production is constrained to be less than 30.9 fb, 12.7 times the Standard Model expectation, at 95% confidence level. The data are also analyzed to probe resonant Higgs boson pair production, constraining a model with an extended Higgs sector based on two doublets and a Randall-Sundrum bulk graviton model. Upper limits are placed on the resonant Higgs boson pair production cross-section times branching ratio, excluding resonances $X$ in the mass range $305~{\rm GeV} < m_X < 402~{\rm GeV}$ in the simplified hMSSM minimal supersymmetric model for $\tan\beta=2$ and excluding bulk Randall-Sundrum gravitons $G_{\mathrm{KK}}$ in the mass range $325~{\rm GeV} < m_{G_{\mathrm{KK}}} < 885~{\rm GeV}$ for $k/\overline{M}_{\mathrm{Pl}} = 1$.
Observed and expected limits at 95% CL on the cross-sections of RS Graviton to HH for k/MPl = 1 process
Observed and expected limits at 95% CL on the cross-sections of RS Graviton to HH for k/MPl = 2 process
Observed and expected limits at 95% CL on the cross-sections of hMSSM scalar X to HH process
A search for pair production of the supersymmetric partners of the Higgs boson (higgsinos $\tilde{H}$) in gauge-mediated scenarios is reported. Each higgsino is assumed to decay to a Higgs boson and a gravitino. Two complementary analyses, targeting high- and low-mass signals, are performed to maximize sensitivity. The two analyses utilize LHC $pp$ collision data at a center-of-mass energy $\sqrt{s} = 13$ TeV, the former with an integrated luminosity of 36.1 fb$^{-1}$ and the latter with 24.3 fb$^{-1}$, collected with the ATLAS detector in 2015 and 2016. The search is performed in events containing missing transverse momentum and several energetic jets, at least three of which must be identified as $b$-quark jets. No significant excess is found above the predicted background. Limits on the cross-section are set as a function of the mass of the $\tilde{H}$ in simplified models assuming production via mass-degenerate higgsinos decaying to a Higgs boson and a gravitino. Higgsinos with masses between 130 and 230 GeV and between 290 and 880 GeV are excluded at the 95% confidence level. Interpretations of the limits in terms of the branching ratio of the higgsino to a $Z$ boson or a Higgs boson are also presented, and a 45% branching ratio to a Higgs boson is excluded for $m_{\tilde{H}} \approx 400$ GeV.
Distribution of m(h1) for events passing the preselection criteria of the high-mass analysis.
Distribution of effective mass for events passing the preselection criteria of the high-mass analysis.
Exclusion limits on higgsino pair production. The results of the low-mass analysis are used below m(higgsino) = 300 GeV, while those of the high-mass analysis are used above. The figure shows the observed and expected 95% upper limits on the higgsino pair production cross-section as a function of m(higgsino).
A search for a heavy neutral Higgs boson, $A$, decaying into a $Z$ boson and another heavy Higgs boson, $H$, is performed using a data sample corresponding to an integrated luminosity of 36.1 fb$^{-1}$ from proton-proton collisions at $\sqrt{s} = 13$ TeV recorded in 2015 and 2016 by the ATLAS detector at the Large Hadron Collider. The search considers the $Z$ boson decaying to electrons or muons and the $H$ boson into a pair of $b$-quarks. No evidence for the production of an $A$ boson is found. Considering each production process separately, the 95% confidence-level upper limits on the $pp\rightarrow A\rightarrow ZH$ production cross-section times the branching ratio $H\rightarrow bb$ are in the range of 14-830 fb for the gluon-gluon fusion process and 26-570 fb for the $b$-associated process for the mass ranges 130-700 GeV of the $H$ boson and process for the mass ranges 130-700 GeV of the $H$ boson and 230-800 GeV of the $A$ boson. The results are interpreted in the context of the two-Higgs-doublet model.
The signal efficiency for the production modes (gluon-gluon fusion and b-associated production) and the signal regions used in the analysis. The efficiency denominator has the total number of generated MC events. The numerator includes the events passing the full signal region selection, including the mbb window cuts. The table shows for each signal mass pair (mA, mH) 3 efficiencies corresponding to the two production modes in the two categories, 2tag and 3tag. These corresponds to "nb = 2 category" and "nb >= 3 category", respectively, of the preprint. No numbers for gluon-gluon fusion in the 3tag category are provided since those are not used in the analysis. The efficiencies are given in fractions.
The cross section times BR(A->ZH) times BR(H->bb) limits for a narrow width A boson produced via gluon-gluon fusion. For each signal point, characterised by the mass pair (mA, mH), two limits are provided, the observed and the expected. The result refers to the nb=2 category only.
The cross section times BR(A->ZH) times BR(H->bb) limits for a narrow width A boson produced in association with b-quarks. For each signal point, characterised by the mass pair (mA, mH), two limits are provided, the observed and the expected. The result refers to the combination of the nb=2 and nb>=3 categories.
This Letter presents a search for the production of a long-lived neutral particle ($Z_d$) decaying within the ATLAS hadronic calorimeter, in association with a Standard Model (SM) $Z$ boson produced via an intermediate scalar boson, where $Z\to l^+l^-$ ($l=e,\mu$). The data used were collected by the ATLAS detector during 2015 and 2016 $pp$ collisions with a center-of-mass energy of $\sqrt{s} = 13$ TeV at the Large Hadron Collider and corresponds to an integrated luminosity of $36.1\pm0.8$ fb$^{-1}$. No significant excess of events is observed above the expected background. Limits on the production cross section of the scalar boson times its decay branching fraction into the long-lived neutral particle are derived as a function of the mass of the intermediate scalar boson, the mass of the long-lived neutral particle, and its $c\tau$ from a few centimeters to one hundred meters. In the case that the intermediate scalar boson is the SM Higgs boson, its decay branching fraction to a long-lived neutral particle with a $c\tau$ approximately between 0.1 m and 7 m is excluded with a 95% confidence level up to 10% for $m_{Z_d}$ between 5 and 15 GeV.
The product of acceptance and efficiency for all signal MC samples.
A search for vectorlike quarks is presented, which targets their decay into a $Z$ boson and a third-generation Standard Model quark. In the case of a vectorlike quark $T$ ($B$) with charge $+2/3e$ ($-1/3e$), the decay searched for is $T \rightarrow Zt$ ($B \rightarrow Zb$). Data for this analysis were taken during 2015 and 2016 with the ATLAS detector at the Large Hadron Collider and correspond to an integrated luminosity of 36.1 fb$^{-1}$ of $pp$ collisions at $\sqrt{s} = 13$ TeV. The final state used is characterized by the presence of $b$-tagged jets, as well as a $Z$ boson with high transverse momentum, which is reconstructed from a pair of opposite-sign same-flavor leptons. Pair and single production of vectorlike quarks are both taken into account and are each searched for using optimized dileptonic exclusive and trileptonic inclusive event selections. In these selections, the high scalar sum of jet transverse momenta, the presence of high-transverse-momentum large-radius jets, as well as - in the case of the single-production selections - the presence of forward jets are used. No significant excess over the background-only hypothesis is found and exclusion limits at 95% confidence level allow masses of vectorlike quarks of $m_T > 1030$ GeV ($m_T > 1210$ GeV) and $m_B > 1010$ GeV ($m_B > 1140$ GeV) in the singlet (doublet) model. In the case of 100% branching ratio for $T\rightarrow Zt$ ($B\rightarrow Zb$), the limits are $m_T > 1340$ GeV ($m_B > 1220$ GeV). Limits at 95% confidence level are also set on the coupling to Standard Model quarks for given vectorlike quark masses.
Comparison of the distribution of the scalar sum of small-$R$ jet transverse momenta, $H_T$, between data and the background prediction in the 0-large-$R$ jet-signal region of the pair-production (PP) $2\ell$ $0-1$J channel. The background prediction is shown post-fit, i.e. after the fit to the data $H_T$ distributions under the background-only hypothesis. The last bin contains the overflow. An example distribution for a $B\bar B$ signal in the singlet model with $m_B$ = 900 GeV is overlaid.
Comparison of the distribution of the scalar sum of small-$R$ jet transverse momenta, $H_T$, between data and the background prediction in the 1-large-$R$ jet-signal region of the pair-production (PP) $2\ell$ $0-1$J channel. The background prediction is shown post-fit, i.e. after the fit to the data $H_T$ distributions under the background-only hypothesis. The last bin contains the overflow. An example distribution for a $B\bar B$ signal in the singlet model with $m_B$ = 900 GeV is overlaid.
Comparison of the distribution of the invariant mass of the $Z$ boson candidate and the highest-$p_T$ $b$-tagged jet, $m(Zb)$, between data and the background prediction in the signal region of the pair-production (PP) $2\ell$ $\geq 2$J channel. The background prediction is shown post-fit, i.e. after the fit to the data $m(Zb)$ distributions under the background-only hypothesis. The last bin contains the overflow. An example distribution for a $B\bar B$ signal in the singlet model with $m_B$ = 900 GeV is overlaid.
A search is presented for the direct pair production of the stop, the supersymmetric partner of the top quark, that decays through an $R$-parity-violating coupling to a final state with two leptons and two jets, at least one of which is identified as a $b$-jet. The dataset corresponds to an integrated luminosity of 36.1 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of $\sqrt{s} = 13$ TeV, collected in 2015 and 2016 by the ATLAS detector at the LHC. No significant excess is observed over the Standard Model background, and exclusion limits are set on stop pair production at a 95% confidence level. Lower limits on the stop mass are set between 600 GeV and 1.5 TeV for branching ratios above 10% for decays to an electron or muon and a $b$-quark.
Signal acceptance (in %) in the (BRe,BRtau) plane for a 800 GeV stop, for the SR800 signal region.
Expected exclusion limit contour in the (BRe,BRtau) plane for a 600 GeV stop. All limits are computed at 95% CL.
Expected exclusion limit contour in the (BRe,BRtau) plane for a 600 GeV stop. All limits are computed at 95% CL.
The production of $Z$ bosons in association with a high-energy photon ($Z\gamma$ production) is studied in the neutrino decay channel of the $Z$ boson using $pp$ collisions at $\sqrt{s}$ = 13 TeV. The analysis uses a data sample with an integrated luminosity of 36.1 fb$^{-1}$ collected by the ATLAS detector at the LHC in 2015 and 2016. Candidate $Z\gamma$ events with invisible decays of the $Z$ boson are selected by requiring significant transverse momentum ($p_{T}$) of the dineutrino system in conjunction with a single isolated photon with large transverse energy ($E_{T}$). The rate of $Z\gamma$ production is measured as a function of photon $E_{T}$, dineutrino system $p_{T}$ and jet multiplicity. Evidence of anomalous triple gauge-boson couplings is sought in $Z\gamma$ production with photon $E_{T}$ greater than 600 GeV. No excess is observed relative to the Standard Model expectation, and upper limits are set on the strength of $ZZ\gamma$ and $Z\gamma\gamma$ couplings.
Measured integrated cross sections for the $Z\gamma$ process for neutrino final states at $\sqrt{s} = 13$ TeV in the extended fiducial region defined in the paper.
Measured differential cross sections for the $pp \rightarrow \nu\bar{\nu}\gamma$ process at $\sqrt{s} = 13$ TeV as a function of photon $E_{T}$ in the inclusive $N_{jets} \geq 0$ extended fiducial region defined in the paper.
Measured differential cross sections for the $pp \rightarrow \nu\bar{\nu}\gamma$ process at $\sqrt{s} = 13$ TeV as a function of photon $E_{T}$ in the exclusive $N_{jets} = 0$ extended fiducial region defined in the paper.
This Letter presents a search for heavy charged long-lived particles produced in proton-proton collisions at $\sqrt{s} = 13$ TeV at the LHC using a data sample corresponding to an integrated luminosity of 36.1 fb$^{-1}$ collected by the ATLAS experiment in 2015 and 2016. These particles are expected to travel with a velocity significantly below the speed of light, and therefore have a specific ionisation higher than any high-momentum Standard Model particle of unit charge. The pixel subsystem of the ATLAS detector is used in this search to measure the ionisation energy loss of all reconstructed charged particles which traverse the pixel detector. Results are interpreted assuming the pair production of $R$-hadrons as composite colourless states of a long-lived gluino and Standard Model partons. No significant deviation from Standard Model background expectations is observed, and lifetime-dependent upper limits on $R$-hadron production cross-sections and gluino masses are set, assuming the gluino always decays in two quarks and a stable neutralino. $R$-hadrons with lifetimes above 1.0 ns are excluded at the 95% confidence level, with lower limits on the gluino mass ranging between 1290 GeV and 2060 GeV. In the case of stable $R$-hadrons, the lower limit on the gluino mass at the 95% confidence level is 1890 GeV.
The number of events in each CR, VR, and SR for the predicted background, for the expected contribution from the signal model normalised to $36.1$ fb$^{-1}$, and in the observed data. The predicted background includes the statistical and systematic uncertainties, respectively. The uncertainty in the signal yield includes all systematic uncertainties except that in the theoretical cross-section.
The number of events in each CR, VR, and SR for the predicted background, for the expected contribution from the signal model normalised to $36.1$ fb$^{-1}$, and in the observed data. The predicted background includes the statistical and systematic uncertainties, respectively. The uncertainty in the signal yield includes all systematic uncertainties except that in the theoretical cross-section.
Expected number of $R$-hadron signal events at different stages of the selection, normalised to $36.1$ fb$^{-1}$. Shown for three different signal points is the number of events expected and the number of events expected in which the selected track has been matched to a generated $R$-hadron. If the gluino decays, it decays to a 100 GeV $\tilde{\chi}^{0}$ and SM quarks.
Searches for non-resonant and resonant Higgs boson pair production are performed in the $\gamma\gamma WW^{*}$ channel with the final state of $\gamma\gamma\ell\nu jj$ using 36.1 fb$^{-1}$ of proton-proton collision data recorded at a centre-of-mass energy of $\sqrt{s} = 13$ TeV by the ATLAS detector at the Large Hadron Collider. No significant deviation from the Standard Model prediction is observed. A 95% confidence-level observed upper limit of 7.7 pb is set on the cross section for non-resonant production, while the expected limit is 5.4 pb. A search for a narrow-width resonance $X$ decaying to a pair of Standard Model Higgs bosons $HH$ is performed with the same set of data, and the observed upper limits on $\sigma(pp \rightarrow X) \times B(X \rightarrow HH)$ range between 40.0 pb and 6.1 pb for masses of the resonance between 260 GeV and 500 GeV, while the expected limits range between 17.6 pb and 4.4 pb. When deriving the limits above, the Standard Model branching ratios of the $H \rightarrow \gamma\gamma$ and $H \rightarrow WW^{*}$ are assumed.
Number of data events without pTyy selection for $m_X$ = 260 GeV.
Number of data events witht pTyy selection for non-resonant.
Observed and expected 95% CL upper limits on the cross-section of gluon-fusion initialted resonant production of the mass of the resonance times the branch ratio (BR) of X to HH with assuming the BR of H to gammagamma and H to WW.
A search is conducted for new resonances decaying into a $W$ or $Z$ boson and a 125 GeV Higgs boson in the $\nu\bar{\nu}b\bar{b}$, $\ell^{\pm}{\nu}b\bar{b}$, and $\ell^+\ell^-b\bar{b}$ final states, where $\ell ^{\pm}= e^{\pm}$ or $\mu^{\pm}$, in $pp$ collisions at $\sqrt s = 13$ TeV. The data used correspond to a total integrated luminosity of 36.1 fb$^{-1}$ collected with the ATLAS detector at the Large Hadron Collider during the 2015 and 2016 data-taking periods. The search is conducted by examining the reconstructed invariant or transverse mass distributions of $Wh$ and $Zh$ candidates for evidence of a localised excess in the mass range of 220 GeV up to 5 TeV. No significant excess is observed and the results are interpreted in terms of constraints on the production cross-section times branching fraction of heavy $W^\prime$ and $Z^\prime$ resonances in heavy-vector-triplet models and the CP-odd scalar boson $A$ in two-Higgs-doublet models. Upper limits are placed at the 95 % confidence level and range between $9.0\times 10^{-4}$ pb and $8.1\times 10^{-1}$ pb depending on the model and mass of the resonance.
Upper limits on Zprime to Z h production cross section x branching fraction in pb
Upper limits on Zprime to Z h production cross section x branching fraction in pb
Upper limits on Wprime to W h production cross section x branching fraction in pb
A search for supersymmetry in events with large missing transverse momentum, jets, and at least one hadronically decaying tau lepton has been performed using 3.2 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV recorded by the ATLAS detector at the Large Hadron Collider in 2015. Two exclusive final states are considered, with either exactly one or at least two tau leptons. No excess over the Standard Model prediction is observed in the data. Results are interpreted in the context of gauge-mediated supersymmetry breaking and a simplified model of gluino pair production with tau-rich cascade decays, substantially improving on previous limits. In the GMSB model considered, supersymmetry-breaking scale ($\Lambda$) values below 92 TeV are excluded at the 95% confidence level, corresponding to gluino masses below 2000 GeV. For large values of $\tan\beta$, values of $\Lambda$ up to 107 TeV and gluino masses up to 2300 GeV are excluded. In the simplified model, gluino masses are excluded up to 1570 GeV for neutralino masses around 100 GeV. Neutralino masses up to 700 GeV are excluded for all gluino masses between 800 GeV and 1500 GeV, while the strongest exclusion of 750 GeV is achieved for gluino masses around 1400 GeV.
mTtau distributions for "extended SR selections" of the 1 tau channel, for the Compressed SR selection without the mTtau > 80 GeV requirement. The last bin includes overflow events. Uncertainties are statistical only. Signal predictions are overlaid for several benchmark models, normalised to their predicted cross sections. For the simplified model, "LM" refers to a low mass splitting, or compressed scenario, with m(gluino)=665 GeV and m(neutralino)=585 GeV; "MM" stands for a medium mass splitting, with m(gluino)=1145 GeV and m(neutralino)=265 GeV; "HM" denotes a high mass splitting scenario, with m(gluino)=1305 GeV and m(neutralino)=105 GeV.
mTtau distributions for "extended SR selections" of the 1 tau channel, for the Medium Mass SR selection without the mTtau > 200 GeV requirement. The last bin includes overflow events. Uncertainties are statistical only. Signal predictions are overlaid for several benchmark models, normalised to their predicted cross sections. For the simplified model, "LM" refers to a low mass splitting, or compressed scenario, with m(gluino)=665 GeV and m(neutralino)=585 GeV; "MM" stands for a medium mass splitting, with m(gluino)=1145 GeV and m(neutralino)=265 GeV; "HM" denotes a high mass splitting scenario, with m(gluino)=1305 GeV and m(neutralino)=105 GeV.
mTtau distributions for "extended SR selections" of the 1 tau channel, for the High Mass SR selection without the mTtau > 200 GeV requirement. The last bin includes overflow events. Uncertainties are statistical only. Signal predictions are overlaid for several benchmark models, normalised to their predicted cross sections. For the simplified model, "LM" refers to a low mass splitting, or compressed scenario, with m(gluino)=665 GeV and m(neutralino)=585 GeV; "MM" stands for a medium mass splitting, with m(gluino)=1145 GeV and m(neutralino)=265 GeV; "HM" denotes a high mass splitting scenario, with m(gluino)=1305 GeV and m(neutralino)=105 GeV.
Ratios of top-quark pair to $Z$-boson cross sections measured from proton--proton collisions at the LHC centre-of-mass energies of $\sqrt s=13$TeV, 8TeV, and 7TeV are presented by the ATLAS Collaboration. Single ratios, at a given $\sqrt s$ for the two processes and at different $\sqrt s$ for each process, as well as double ratios of the two processes at different $\sqrt s$, are evaluated. The ratios are constructed using previously published ATLAS measurements of the $t\overline{t}$ and $Z$-boson production cross sections, corrected to a common phase space where required, and a new analysis of $Z \rightarrow \ell^+ \ell^-$ where $\ell=e,\mu$ at $\sqrt s=13$TeV performed with data collected in 2015 with an integrated luminosity of $3.2$fb$^{-1}$. Correlations of systematic uncertainties are taken into account when evaluating the uncertainties in the ratios. The correlation model is also used to evaluate the combined cross section of the $Z\rightarrow e^+e^-$ and the $Z\rightarrow \mu^+ \mu^-$ channels for each $\sqrt s$ value. The results are compared to calculations performed at next-to-next-to-leading-order accuracy using recent sets of parton distribution functions. The data demonstrate significant power to constrain the gluon distribution function for the Bjorken-$x$ values near 0.1 and the light-quark sea for $x<0.02$.
Measured fiducial cross section times leptonic branching ratio for Z/gamma* production in the Z/gamma* -> e+e- final state at 13TeV.
Measured fiducial cross section times leptonic branching ratio for Z/gamma* production in the Z/gamma* -> mu+ mu- final state at 13TeV.
Breakdown of systematic uncertainties in percent for the measured fiducial cross section times leptonic branching ratio for Z/gamma* production in the Z/gamma* -> e+e- final state at 13TeV.
Several extensions of the Standard Model predict associated production of dark-matter particles with a Higgs boson. Such processes are searched for in final states with missing transverse momentum and a Higgs boson decaying to a $b\bar b$ pair with the ATLAS detector using 36.1 fb$^{-1}$ of $pp$ collisions at a center-of-mass energy of 13 TeV at the LHC. The observed data are in agreement with the Standard Model predictions and limits are placed on the associated production of dark-matter particles and a Higgs boson.
Distributions of the invariant mass of the Higgs boson candidates mh=m_J with one b-tag in the SR for the fourth MET category which is used as input to the fit.
Distributions of the invariant mass of the Higgs boson candidates mh=m_jj with two b-tags in the SR for the first MET category that is used as input to the fit.
Distributions of the invariant mass of the Higgs boson candidates mh=m_jj with two b-tags in the SR for the second MET category that is used as input to the fit.
Charged Higgs bosons produced either in top-quark decays or in association with a top-quark, subsequently decaying via $H^{\pm} \to \tau^{\pm}\nu_{\tau}$, are searched for in 36.1 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV recorded with the ATLAS detector. Depending on whether the top-quark produced together with $H^{\pm}$ decays hadronically or leptonically, the search targets $\tau$+jets and $\tau$+lepton final states, in both cases with a hadronically decaying $\tau$-lepton. No evidence of a charged Higgs boson is found. For the mass range of $m_{H^{\pm}}$ = 90-2000 GeV, upper limits at the 95% confidence level are set on the production cross-section of the charged Higgs boson times the branching fraction $\mathrm{B}(H^{\pm} \to \tau^{\pm}\nu_{\tau})$ in the range 4.2-0.0025 pb. In the mass range 90-160 GeV, assuming the Standard Model cross-section for $t\overline{t}$ production, this corresponds to upper limits between 0.25% and 0.031% for the branching fraction $\mathrm{B}(t\to bH^{\pm}) \times \mathrm{B}(H^{\pm} \to \tau^{\pm}\nu_{\tau})$.
Observed and expected 95% CL exclusion limits on $\sigma(pp\to tbH^+)\times \mathrm{\cal{B}}(H^+\to\tau\nu)$ as a function of the charged Higgs boson mass in 36.1 fb$^{-1}$ of $pp$ collision data at $\sqrt{s} = 13$ TeV, after combination of the $\tau_{\rm had-vis}$+jets and $\tau_{\rm had-vis}$+lepton final states.
Observed and expected 95% CL exclusion limits on $\mathrm{\cal{B}}(t\to bH^+)\times\mathrm{\cal{B}}(H^+\to\tau\nu)$ as a function of the charged Higgs boson mass in 36.1 fb$^{-1}$ of $pp$ collision data at $\sqrt{s} = 13$ TeV, after combination of the $\tau_{\rm had-vis}$+jets and $\tau_{\rm had-vis}$+lepton final states.
Observed 95% CL exclusion contour in the tan$\beta$ - $m_H$ plane shown in the context of the hMSSM, for the regions in which theoretical predictions are available (0.5$\leq\text{tan}\beta\leq60$).
A combined measurement of differential and inclusive total cross sections of Higgs boson production is performed using 36.1 fb$^{-1}$ of 13 TeV proton-proton collision data produced by the LHC and recorded by the ATLAS detector in 2015 and 2016. Cross sections are obtained from measured $H \rightarrow \gamma \gamma$ and $H \rightarrow ZZ^* \rightarrow 4\ell$ event yields, which are combined taking into account detector efficiencies, resolution, acceptances and branching fractions. The total Higgs boson production cross section is measured to be 57.0$^{+6.0}_{-5.9}$ (stat.) $^{+4.0}_{-3.3}$ (syst.) pb, in agreement with the Standard Model prediction. Differential cross-section measurements are presented for the Higgs boson transverse momentum distribution, Higgs boson rapidity, number of jets produced together with the Higgs boson, and the transverse momentum of the leading jet. The results from the two decay channels are found to be compatible, and their combination agrees with the Standard Model predictions.
Differential cross sections in the full phase space obtained from the H->gammagamma and H->4l combined measurement for Higgs boson transverse momentum ptH. The NNLOPS ggF prediction scaled to the N3LO cross section is also provided.
Differential cross sections in the full phase space obtained from the H->gammagamma and H->4l combined measurement for the Higgs boson rapidity |yH|. The NNLOPS ggF prediction scaled to the N3LO cross section is also provided.
Differential cross sections in the full phase space obtained from the H->gammagamma and H->4l combined measurement for the number of jets Njets with pT > 30 GeV. The NNLOPS ggF prediction scaled to the N3LO cross section is also provided.
A search for supersymmetric partners of top quarks decaying as $\tilde{t}_1\to c\tilde\chi^0_1$ and supersymmetric partners of charm quarks decaying as $\tilde{c}_1\to c\tilde\chi^0_1$, where $\tilde\chi^0_1$ is the lightest neutralino, is presented. The search uses 36.1 ${\rm fb}^{-1}$ $pp$ collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS experiment at the Large Hadron Collider and is performed in final states with jets identified as containing charm hadrons. Assuming a 100% branching ratio to $c\tilde\chi^0_1$, top and charm squarks with masses up to 850 GeV are excluded at 95% confidence level for a massless lightest neutralino. For $m_{\tilde{t}_1,\tilde{c}_1}-m_{\tilde\chi^0_1}
Acceptance for best expected CLS SR in the $\tilde{t}_1/\tilde{c}_1-\tilde{\chi}_1^0$ mass plane.
Acceptance for SR1 in the $\tilde{t}_1/\tilde{c}_1-\tilde{\chi}_1^0$ mass plane.
Acceptance for SR1 in the $\tilde{t}_1/\tilde{c}_1-\tilde{\chi}_1^0$ mass plane.
An observation of electroweak $W^{\pm}Z$ production in association with two jets in proton-proton collisions is presented. The data collected by the ATLAS detector at the Large Hadron Collider in 2015 and 2016 at a centre-of-mass energy of $\sqrt{s} =$ 13 TeV are used, corresponding to an integrated luminosity of 36.1 fb$^{-1}$. Events containing three identified leptons, either electrons or muons, and two jets are selected. The electroweak production of $W^{\pm}Z$ bosons in association with two jets is measured with an observed significance of 5.3 standard deviations. A fiducial cross-section for electroweak production including interference effects is measured to be $\sigma_{WZjj\mathrm{-EW}} = 0.57 \; ^{+ 0.14} _{- 0.13} \,(\mathrm{stat.}) \; ^{+ 0.07} _{- 0.06} \,(\mathrm{syst.}) \; \mathrm{fb}$. Total and differential fiducial cross-sections of the sum of $W^\pm Z jj$ electroweak and strong productions for several kinematic observables are also measured.
Fiducial cross section of the electroweak $W^{\pm}Z$ boson pair production in association with two jets. The first systematic uncertainty is experimental, the second is the theory modelling and interference systematics and the third one is the luminosity uncertainty.
Fiducial cross section of the $W^{\pm}Z$ boson pair production in association with two jets. The first systematic uncertainty is experimental, the second is the theory modelling and interference systematics and the third one is the luminosity uncertainty.
Numbers of observed and expected events in the $W^{\pm}Zjj$ signal region and in the three control regions, before the fit. The expected number of $WZjj-EW$ events from $SHERPA$ and the estimated number of background events from the other processes are shown. The sum of the background containing misidentified leptons is labelled "Misid. leptons". The total uncertainties are quoted.
A search for heavy right-handed Majorana or Dirac neutrinos $N_R$ and heavy right-handed gauge bosons $W_R$ is performed in events with a pair of energetic electrons or muons, with the same or opposite electric charge, and two energetic jets. The events are selected from $pp$ collision data with an integrated luminosity of 36.1 fb$^{-1}$ collected by the ATLAS detector at $\sqrt{s}$ = 13 TeV. No significant deviations from the Standard Model are observed. The results are interpreted within the theoretical framework of a left-right symmetric model and lower limits are set on masses in the heavy right-handed $W$ boson and neutrino mass plane. The excluded region extends to $m_{W_R}=4.7$ TeV for both Majorana and Dirac $N_R$ neutrinos.
Expected 95% CL exclusion contour in the $m_{W_R}–m_{N_R}$ plane for the Majorana $N_R$ neutrino $ee$ channel.
Observed 95% CL exclusion contour in the $m_{W_R}–m_{N_R}$ plane for the Majorana $N_R$ neutrino $ee$ channel.
Observed and expected 95% CL exclusion, for the tested signal mass hypotheses in the $m_{W_R}–m_{N_R}$ plane, for the Majorana $N_R$ neutrino $ee$ channel.
This paper presents measurements of $W^{\pm}Z$ production cross sections in $pp$ collisions at a centre-of-mass energy of 13 TeV. The data were collected in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider, and correspond to an integrated luminosity of 36.1 fb$^{-1}$. The $W^{\pm}Z$ candidate events are reconstructed using leptonic decay modes of the gauge bosons into electrons and muons. The measured inclusive cross section in the detector fiducial region for a single leptonic decay mode is $\sigma_{W^\pm Z \rightarrow \ell^{'} \nu \ell \ell}^{\textrm{fid.}} = 63.7 \pm 1.0$ (stat.) $\pm 2.3$ (syst.) $\pm 1.4$ (lumi.) fb, reproduced by the next-to-next-to-leading-order Standard Model prediction of $61.5^{+1.4}_{-1.3}$ fb. Cross sections for $W^+Z$ and $W^-Z$ production and their ratio are presented as well as differential cross sections for several kinematic observables. An analysis of angular distributions of leptons from decays of $W$ and $Z$ bosons is performed for the first time in pair-produced events in hadronic collisions, and integrated helicity fractions in the detector fiducial region are measured for the $W$ and $Z$ bosons separately. Of particular interest, the longitudinal helicity fraction of pair-produced vector bosons is also measured.
The measured $W^{\pm}Z$ fiducial cross section in the four channels and their combination. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity uncertainty, the second is the modelling uncertainty, the third is luminosity uncertainty.
The measured $W^{+}Z$ fiducial cross section in the four channels and their combination. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity uncertainty, the second is the modelling uncertainty, the third is luminosity uncertainty.
The measured $W^{-}Z$ fiducial cross section in the four channels and their combination. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity uncertainty, the second is the modelling uncertainty, the third is luminosity uncertainty.
A search for electroweak production of supersymmetric particles is performed in two-lepton and three-lepton final states using recursive jigsaw reconstruction. The search uses data collected in 2015 and 2016 by the ATLAS experiment in $\sqrt{s}$ = 13 TeV proton--proton collisions at the CERN Large Hadron Collider corresponding to an integrated luminosity of 36.1 fb$^{-1}$. Chargino-neutralino pair production, with decays via W/Z bosons, is studied in final states involving leptons and jets and missing transverse momentum for scenarios with large and intermediate mass-splittings between the parent particle and lightest supersymmetric particle, as well as for the scenario where this mass splitting is close to the mass of the Z boson. The latter case is challenging since the vector bosons are produced with kinematic properties that are similar to those in Standard Model processes. Results are found to be compatible with the Standard Model expectations in the signal regions targeting large and intermediate mass-splittings, and chargino-neutralino masses up to 600 GeV are excluded at 95% confidence level for a massless lightest supersymmetric particle. Excesses of data above the expected background are found in the signal regions targeting low mass-splittings, and the largest local excess amounts to 3.0 standard deviations.
Distributions of kinematic variables in the signal regions for the $2\ell$ channels after applying all selection requirements. The histograms show the post-fit background predictions. The last bin includes the overflow. The distribution for $H_{4,1}^{\textrm{PP}}$ in SR$2\ell$_Low is plotted. The expected distribution for a benchmark signal model, normalized to the NLO+NLL cross-section times integrated luminosity, is also shown for comparison.
Distributions of kinematic variables in the signal regions for the $2\ell$ channels after applying all selection requirements. The histograms show the post-fit background predictions. The last bin includes the overflow. The distribution for $\textrm{min}(H^{\textrm{P}_{\textrm{a}}}_{1,1},H^{\textrm{P}_{\textrm{b}}}_{1,1})/\textrm{min}(H^{\textrm{P}_{\textrm{a}}}_{2,1},H^{\textrm{P}_{\textrm{b}}}_{2,1})$ in SR$2\ell$_Low is plotted. The expected distribution for a benchmark signal model, normalized to the NLO+NLL cross-section times integrated luminosity, is also shown for comparison.
Distributions of kinematic variables in the signal regions for the $2\ell$ channels after applying all selection requirements. The histograms show the post-fit background predictions. The last bin includes the overflow. The distribution for $p_{\mathrm{T\ ISR}}^{~\textrm{CM}}$ in SR2$\ell$_ISR is plotted. The expected distribution for a benchmark signal model, normalized to the NLO+NLL cross-section times integrated luminosity, is also shown for comparison.
A search for the supersymmetric partners of the Standard Model bottom and top quarks is presented. The search uses 36.1 fb$^{-1}$ of $pp$ collision data at $\sqrt{s}=13$ TeV collected by the ATLAS experiment at the Large Hadron Collider. Direct production of pairs of bottom and top squarks ($\tilde{b}_{1}$ and $\tilde{t}_{1}$) is searched for in final states with $b$-tagged jets and missing transverse momentum. Distinctive selections are defined with either no charged leptons (electrons or muons) in the final state, or one charged lepton. The zero-lepton selection targets models in which the $\tilde{b}_{1}$ is the lightest squark and decays via $\tilde{b}_{1} \rightarrow b \tilde{\chi}^{0}_{1}$, where $\tilde{\chi}^{0}_{1}$ is the lightest neutralino. The one-lepton final state targets models where bottom or top squarks are produced and can decay into multiple channels, $\tilde{b}_{1} \rightarrow b \tilde{\chi}^{0}_{1}$ and $\tilde{b}_{1} \rightarrow t \tilde{\chi}^{\pm}_{1}$, or $\tilde{t}_{1} \rightarrow t \tilde{\chi}^{0}_{1}$ and $\tilde{t}_{1} \rightarrow b \tilde{\chi}^{\pm}_{1}$, where $\tilde{\chi}^{\pm}_{1}$ is the lightest chargino and the mass difference $m_{\tilde{\chi}^{\pm}_{1}}- m_{\tilde{\chi}^{0}_{1}}$ is set to 1 GeV. No excess above the expected Standard Model background is observed. Exclusion limits at 95\% confidence level on the mass of third-generation squarks are derived in various supersymmetry-inspired simplified models.
- - - - - - - - - - - - - - - - - - - - <br/><b>Acceptance:</b><br/><i>symmetric:</i> <a href="79165?version=1&table=Acceptance1">b0L-SRA350</a> <a href="79165?version=1&table=Acceptance2">b0L-SRA450</a> <a href="79165?version=1&table=Acceptance3">b0L-SRA550</a> <a href="79165?version=1&table=Acceptance4">b0L-SRB</a> <a href="79165?version=1&table=Acceptance5">b0L-SRC</a> <a href="79165?version=1&table=Acceptance6">b0L-best</a><br/><i>asymmetric:</i> <a href="79165?version=1&table=Acceptance7">b1L-SRA300-2j</a> <a href="79165?version=1&table=Acceptance8">b1L-SRA450</a> <a href="79165?version=1&table=Acceptance9">b1L-SRA600</a> <a href="79165?version=1&table=Acceptance10">b1L-SRA750</a> <a href="79165?version=1&table=Acceptance11">b1L-SRB</a> <a href="79165?version=1&table=Acceptance12">b1L-best</a><br/><br/><b>Efficiency:</b><br/><i>symmetric:</i> <a href="79165?version=1&table=Efficiency1">b0L-SRA350</a> <a href="79165?version=1&table=Efficiency2">b0L-SRA450</a> <a href="79165?version=1&table=Efficiency3">b0L-SRA550</a> <a href="79165?version=1&table=Efficiency4">b0L-SRB</a> <a href="79165?version=1&table=Efficiency5">b0L-SRC</a> <a href="79165?version=1&table=Efficiency6">b0L-best</a><br/><i>asymmetric:</i> <a href="79165?version=1&table=Efficiency7">b1L-SRA300-2j</a> <a href="79165?version=1&table=Efficiency8">b1L-SRA450</a> <a href="79165?version=1&table=Efficiency9">b1L-SRA600</a> <a href="79165?version=1&table=Efficiency10">b1L-SRA750</a> <a href="79165?version=1&table=Efficiency11">b1L-SRB</a> <a href="79165?version=1&table=Efficiency12">b1L-best</a><br/><br/><b>Best SR Mapping:</b><br/><i>symmetric:</i> <a href="79165?version=1&table=BestSR4">b0L</a><br/><i>asymmetric:</i> <a href="79165?version=1&table=BestSR1">b1L</a> <a href="79165?version=1&table=BestSR2">b0L</a> <a href="79165?version=1&table=BestSR3">combined</a><br/><br/><b>Exclusion Contour:</b><br/><i>symmetric:</i> b0L-SRA350 <a href="79165?version=1&table=Contour1">exp</a> <a href="79165?version=1&table=Contour2">obs</a> b0L-SRA450 <a href="79165?version=1&table=Contour5">exp</a> <a href="79165?version=1&table=Contour6">obs</a> b0L-SRA550 <a href="79165?version=1&table=Contour9">exp</a> <a href="79165?version=1&table=Contour10">obs</a> b0L-SRB <a href="79165?version=1&table=Contour11">exp</a> <a href="79165?version=1&table=Contour12">obs</a> b0L-SRC <a href="79165?version=1&table=Contour15">exp</a> <a href="79165?version=1&table=Contour16">obs</a> b0L-best <a href="79165?version=1&table=Contour17">exp</a> <a href="79165?version=1&table=Contour18">obs</a><br/><i>asymmetric:</i> b0L-SRA350 <a href="79165?version=1&table=Contour3">exp</a> <a href="79165?version=1&table=Contour4">obs</a> b0L-SRA450 <a href="79165?version=1&table=Contour7">exp</a> <a href="79165?version=1&table=Contour8">obs</a> b0L-SRB <a href="79165?version=1&table=Contour13">exp</a> <a href="79165?version=1&table=Contour14">obs</a> b0L-best <a href="79165?version=1&table=Contour19">exp</a> <a href="79165?version=1&table=Contour20">obs</a> b1L-SRA300-2j <a href="79165?version=1&table=Contour21">exp</a> <a href="79165?version=1&table=Contour22">obs</a> b1L-SRA450 <a href="79165?version=1&table=Contour23">exp</a> <a href="79165?version=1&table=Contour24">obs</a> b1L-SRA600 <a href="79165?version=1&table=Contour25">exp</a> <a href="79165?version=1&table=Contour26">obs</a> b1L-SRA750 <a href="79165?version=1&table=Contour27">exp</a> <a href="79165?version=1&table=Contour28">obs</a> b1L-SRB <a href="79165?version=1&table=Contour29">exp</a> <a href="79165?version=1&table=Contour30">obs</a> b1L-best <a href="79165?version=1&table=Contour31">exp</a> <a href="79165?version=1&table=Contour32">obs</a> A-LowMass <a href="79165?version=1&table=Contour33">exp</a> <a href="79165?version=1&table=Contour34">obs</a> A-HighMass <a href="79165?version=1&table=Contour35">exp</a> <a href="79165?version=1&table=Contour36">obs</a> B combination <a href="79165?version=1&table=Contour37">exp</a> <a href="79165?version=1&table=Contour38">obs</a> Best combination <a href="79165?version=1&table=Contour39">exp</a> <a href="79165?version=1&table=Contour40">obs</a><br/><br/><b>SR Distribution:</b><br/><a href="79165?version=1&table=SRdistribution1">b0L-SRA</a>: $m_{\mathrm{CT}}$ <a href="79165?version=1&table=SRdistribution2">b0L-SRB</a>: $\mathrm{min[m_{T}(jet_{1-4}, E_{T}^{miss})]}$ <a href="79165?version=1&table=SRdistribution3">b0L-SRC</a>: ${\cal A}$ <a href="79165?version=1&table=SRdistribution4">b1L-SRA300-2j</a>: $\mathrm{m_{bb}}$ <a href="79165?version=1&table=SRdistribution5">b1L-SRA</a>: $\mathrm{m_{eff}}$ <a href="79165?version=1&table=SRdistribution6">b1L-SRB</a>: $\mathrm{m_{T}}$<br/><br/><b>Cross section upper limit:</b><br/><i>symmetric:</i> <a href="79165?version=1&table=Limitoncrosssection1">b0L-best</a> <a href="79165?version=1&table=Limitoncrosssection2">b0L-SRA350</a> <a href="79165?version=1&table=Limitoncrosssection3">b0L-SRA450</a> <a href="79165?version=1&table=Limitoncrosssection4">b0L-SRA550</a> <a href="79165?version=1&table=Limitoncrosssection5">b0L-SRB</a> <a href="79165?version=1&table=Limitoncrosssection6">b0L-SRC</a><br/><i>asymmetric:</i> <a href="79165?version=1&table=Limitoncrosssection7">b0L-best</a> <a href="79165?version=1&table=Limitoncrosssection8">b0L-SRA350</a> <a href="79165?version=1&table=Limitoncrosssection9">b0L-SRA450</a> <a href="79165?version=1&table=Limitoncrosssection10">b0L-SRB</a> <a href="79165?version=1&table=Limitoncrosssection11">b1L-best</a> <a href="79165?version=1&table=Limitoncrosssection12">b1L-SRA300-2j</a> <a href="79165?version=1&table=Limitoncrosssection13">b1L-SRA450</a> <a href="79165?version=1&table=Limitoncrosssection14">b1L-SRA600</a> <a href="79165?version=1&table=Limitoncrosssection15">b1L-SRA750</a> <a href="79165?version=1&table=Limitoncrosssection16">b1L-SRB</a> <a href="79165?version=1&table=Limitoncrosssection17">best combination</a> <a href="79165?version=1&table=Limitoncrosssection18">A-LowMass</a> <a href="79165?version=1&table=Limitoncrosssection19">A-HighMass</a> <a href="79165?version=1&table=Limitoncrosssection20">B combination</a><br/><br/><b>Cutflow:</b><br/><i>symmetric:</i> <a href="79165?version=1&table=CutflowTable1">b0L-SRA (1 TeV, 1 GeV)</a> <a href="79165?version=1&table=CutflowTable2">b0L-SRB (700 GeV, 450 GeV)</a> <a href="79165?version=1&table=CutflowTable3">b0L-SRC (450 GeV, 430 GeV)</a><br/><i>mixed:</i> <a href="79165?version=1&table=CutflowTable4">b1L-SRA (700 GeV, 300 GeV)</a> <a href="79165?version=1&table=CutflowTable5">b1L-SRA300-2j (700 GeV, 300 GeV)</a> <a href="79165?version=1&table=CutflowTable6">b0L-SRA (700 GeV, 300 GeV)</a><br/><br/><b>Truth Code</b> and <b>SLHA Files</b> for the cutflows are available under "Resources" (purple button on the left)
- - - - - - - - - - - - - - - - - - - - <br/><b>Acceptance:</b><br/><i>symmetric:</i> <a href="79165?version=1&table=Acceptance1">b0L-SRA350</a> <a href="79165?version=1&table=Acceptance2">b0L-SRA450</a> <a href="79165?version=1&table=Acceptance3">b0L-SRA550</a> <a href="79165?version=1&table=Acceptance4">b0L-SRB</a> <a href="79165?version=1&table=Acceptance5">b0L-SRC</a> <a href="79165?version=1&table=Acceptance6">b0L-best</a><br/><i>asymmetric:</i> <a href="79165?version=1&table=Acceptance7">b1L-SRA300-2j</a> <a href="79165?version=1&table=Acceptance8">b1L-SRA450</a> <a href="79165?version=1&table=Acceptance9">b1L-SRA600</a> <a href="79165?version=1&table=Acceptance10">b1L-SRA750</a> <a href="79165?version=1&table=Acceptance11">b1L-SRB</a> <a href="79165?version=1&table=Acceptance12">b1L-best</a><br/><br/><b>Efficiency:</b><br/><i>symmetric:</i> <a href="79165?version=1&table=Efficiency1">b0L-SRA350</a> <a href="79165?version=1&table=Efficiency2">b0L-SRA450</a> <a href="79165?version=1&table=Efficiency3">b0L-SRA550</a> <a href="79165?version=1&table=Efficiency4">b0L-SRB</a> <a href="79165?version=1&table=Efficiency5">b0L-SRC</a> <a href="79165?version=1&table=Efficiency6">b0L-best</a><br/><i>asymmetric:</i> <a href="79165?version=1&table=Efficiency7">b1L-SRA300-2j</a> <a href="79165?version=1&table=Efficiency8">b1L-SRA450</a> <a href="79165?version=1&table=Efficiency9">b1L-SRA600</a> <a href="79165?version=1&table=Efficiency10">b1L-SRA750</a> <a href="79165?version=1&table=Efficiency11">b1L-SRB</a> <a href="79165?version=1&table=Efficiency12">b1L-best</a><br/><br/><b>Best SR Mapping:</b><br/><i>symmetric:</i> <a href="79165?version=1&table=BestSR4">b0L</a><br/><i>asymmetric:</i> <a href="79165?version=1&table=BestSR1">b1L</a> <a href="79165?version=1&table=BestSR2">b0L</a> <a href="79165?version=1&table=BestSR3">combined</a><br/><br/><b>Exclusion Contour:</b><br/><i>symmetric:</i> b0L-SRA350 <a href="79165?version=1&table=Contour1">exp</a> <a href="79165?version=1&table=Contour2">obs</a> b0L-SRA450 <a href="79165?version=1&table=Contour5">exp</a> <a href="79165?version=1&table=Contour6">obs</a> b0L-SRA550 <a href="79165?version=1&table=Contour9">exp</a> <a href="79165?version=1&table=Contour10">obs</a> b0L-SRB <a href="79165?version=1&table=Contour11">exp</a> <a href="79165?version=1&table=Contour12">obs</a> b0L-SRC <a href="79165?version=1&table=Contour15">exp</a> <a href="79165?version=1&table=Contour16">obs</a> b0L-best <a href="79165?version=1&table=Contour17">exp</a> <a href="79165?version=1&table=Contour18">obs</a><br/><i>asymmetric:</i> b0L-SRA350 <a href="79165?version=1&table=Contour3">exp</a> <a href="79165?version=1&table=Contour4">obs</a> b0L-SRA450 <a href="79165?version=1&table=Contour7">exp</a> <a href="79165?version=1&table=Contour8">obs</a> b0L-SRB <a href="79165?version=1&table=Contour13">exp</a> <a href="79165?version=1&table=Contour14">obs</a> b0L-best <a href="79165?version=1&table=Contour19">exp</a> <a href="79165?version=1&table=Contour20">obs</a> b1L-SRA300-2j <a href="79165?version=1&table=Contour21">exp</a> <a href="79165?version=1&table=Contour22">obs</a> b1L-SRA450 <a href="79165?version=1&table=Contour23">exp</a> <a href="79165?version=1&table=Contour24">obs</a> b1L-SRA600 <a href="79165?version=1&table=Contour25">exp</a> <a href="79165?version=1&table=Contour26">obs</a> b1L-SRA750 <a href="79165?version=1&table=Contour27">exp</a> <a href="79165?version=1&table=Contour28">obs</a> b1L-SRB <a href="79165?version=1&table=Contour29">exp</a> <a href="79165?version=1&table=Contour30">obs</a> b1L-best <a href="79165?version=1&table=Contour31">exp</a> <a href="79165?version=1&table=Contour32">obs</a> A-LowMass <a href="79165?version=1&table=Contour33">exp</a> <a href="79165?version=1&table=Contour34">obs</a> A-HighMass <a href="79165?version=1&table=Contour35">exp</a> <a href="79165?version=1&table=Contour36">obs</a> B combination <a href="79165?version=1&table=Contour37">exp</a> <a href="79165?version=1&table=Contour38">obs</a> Best combination <a href="79165?version=1&table=Contour39">exp</a> <a href="79165?version=1&table=Contour40">obs</a><br/><br/><b>SR Distribution:</b><br/><a href="79165?version=1&table=SRdistribution1">b0L-SRA</a>: $m_{\mathrm{CT}}$ <a href="79165?version=1&table=SRdistribution2">b0L-SRB</a>: $\mathrm{min[m_{T}(jet_{1-4}, E_{T}^{miss})]}$ <a href="79165?version=1&table=SRdistribution3">b0L-SRC</a>: ${\cal A}$ <a href="79165?version=1&table=SRdistribution4">b1L-SRA300-2j</a>: $\mathrm{m_{bb}}$ <a href="79165?version=1&table=SRdistribution5">b1L-SRA</a>: $\mathrm{m_{eff}}$ <a href="79165?version=1&table=SRdistribution6">b1L-SRB</a>: $\mathrm{m_{T}}$<br/><br/><b>Cross section upper limit:</b><br/><i>symmetric:</i> <a href="79165?version=1&table=Limitoncrosssection1">b0L-best</a> <a href="79165?version=1&table=Limitoncrosssection2">b0L-SRA350</a> <a href="79165?version=1&table=Limitoncrosssection3">b0L-SRA450</a> <a href="79165?version=1&table=Limitoncrosssection4">b0L-SRA550</a> <a href="79165?version=1&table=Limitoncrosssection5">b0L-SRB</a> <a href="79165?version=1&table=Limitoncrosssection6">b0L-SRC</a><br/><i>asymmetric:</i> <a href="79165?version=1&table=Limitoncrosssection7">b0L-best</a> <a href="79165?version=1&table=Limitoncrosssection8">b0L-SRA350</a> <a href="79165?version=1&table=Limitoncrosssection9">b0L-SRA450</a> <a href="79165?version=1&table=Limitoncrosssection10">b0L-SRB</a> <a href="79165?version=1&table=Limitoncrosssection11">b1L-best</a> <a href="79165?version=1&table=Limitoncrosssection12">b1L-SRA300-2j</a> <a href="79165?version=1&table=Limitoncrosssection13">b1L-SRA450</a> <a href="79165?version=1&table=Limitoncrosssection14">b1L-SRA600</a> <a href="79165?version=1&table=Limitoncrosssection15">b1L-SRA750</a> <a href="79165?version=1&table=Limitoncrosssection16">b1L-SRB</a> <a href="79165?version=1&table=Limitoncrosssection17">best combination</a> <a href="79165?version=1&table=Limitoncrosssection18">A-LowMass</a> <a href="79165?version=1&table=Limitoncrosssection19">A-HighMass</a> <a href="79165?version=1&table=Limitoncrosssection20">B combination</a><br/><br/><b>Cutflow:</b><br/><i>symmetric:</i> <a href="79165?version=1&table=CutflowTable1">b0L-SRA (1 TeV, 1 GeV)</a> <a href="79165?version=1&table=CutflowTable2">b0L-SRB (700 GeV, 450 GeV)</a> <a href="79165?version=1&table=CutflowTable3">b0L-SRC (450 GeV, 430 GeV)</a><br/><i>mixed:</i> <a href="79165?version=1&table=CutflowTable4">b1L-SRA (700 GeV, 300 GeV)</a> <a href="79165?version=1&table=CutflowTable5">b1L-SRA300-2j (700 GeV, 300 GeV)</a> <a href="79165?version=1&table=CutflowTable6">b0L-SRA (700 GeV, 300 GeV)</a><br/><br/><b>Truth Code</b> and <b>SLHA Files</b> for the cutflows are available under "Resources" (purple button on the left)
Signal acceptance (in %) in the ( M(SBOTTOM), M(NEUTRALINO) ) mass plane for the symmetric decay of the sbottom into bottom quark and neutralino, for the b0L-SRA350 signal region.
A search for charged Higgs bosons heavier than the top quark and decaying via $H^\pm \rightarrow tb$ is presented. The data analysed corresponds to 36.1 fb$^{-1}$ of $pp$ collisions at $\sqrt{s}$ = 13 TeV and was recorded with the ATLAS detector at the LHC in 2015 and 2016. The production of a charged Higgs boson in association with a top quark and a bottom quark, $pp \rightarrow tb H^\pm$, is explored in the mass range from $m_{H^\pm}$ = 200 to 2000 GeV using multi-jet final states with one or two electrons or muons. Events are categorised according to the multiplicity of jets and how likely these are to have originated from hadronisation of a bottom quark. Multivariate techniques are used to discriminate between signal and background events. No significant excess above the background-only hypothesis is observed and exclusion limits are derived for the production cross-section times branching fraction of a charged Higgs boson as a function of its mass, which range from 2.9 pb at $m_{H^\pm}$ = 200 GeV to 0.070 pb at $m_{H^\pm}$ = 2000 GeV. The results are interpreted in two benchmark scenarios of the Minimal Supersymmetric Standard Model.
Expected and observed limits for the production of $H^{+} \to tb$ in association with a top quark and a bottom quark. The bands surrounding the expected limit show the 68% and 95% confidence intervals. The limits are based on the combination of the $\ell+$jets and $\ell\ell$ final states. Theory predictions are shown for three representative values of $\tan\beta$ in the $m_h^{\mathrm{mod-}}$ benchmark scenario. Uncertainties in the predicted $H^+$ cross-sections or branching ratios are not considered.
Expected and observed upper limits on $\tan\beta$ as a function of $m_{H^{+}}$ in the $m_h^{\mathrm{mod-}}$ scenario of the MSSM. Limits are shown for $\tan\beta$ values in the range of 0.5-60, where predictions are available from both scenarios. The bands surrounding the expected limits show the 68% and 95% confidence intervals. The limits are based on the combination of the $\ell+$jets and $\ell\ell$ final states. The production cross-section of $t\bar{t}H$ and $tH$, as well as the branching ratios of the $H$, are fixed to their SM values at each point in the plane. Uncertainties on the predicted $H^{+}$ cross-sections or branching ratios are not considered.
Expected and observed lower limits on $\tan\beta$ as a function of $m_{H^{+}}$ in the $m_h^{\mathrm{mod-}}$ scenario of the MSSM. Limits are shown for $\tan\beta$ values in the range of 0.5-60, where predictions are available from both scenarios. The bands surrounding the expected limits show the 68% and 95% confidence intervals. The limits are based on the combination of the $\ell+$jets and $\ell\ell$ final states. The production cross-section of $t\bar{t}H$ and $tH$, as well as the branching ratios of the $H$, are fixed to their SM values at each point in the plane. Uncertainties on the predicted $H^{+}$ cross-sections or branching ratios are not considered.
Properties of the Higgs boson are measured in the two-photon final state using 36.1 fb$^{-1}$ of proton-proton collision data recorded at $\sqrt{s} = 13$ TeV by the ATLAS experiment at the Large Hadron Collider. Cross-section measurements for the production of a Higgs boson through gluon-gluon fusion, vector-boson fusion, and in association with a vector bosonor a top-quark pair are reported. The signal strength, defined as the ratio of the observed to the expected signal yield, is measured for each of these production processes as well as inclusively. The global signal strength measurement of $0.99 \pm 0.14$ improves on the precision of the ATLAS measurement at $\sqrt{s} = 7$ and 8 TeV by a factor of two. Measurements of gluon-gluon fusion and vector-boson fusion productions yield signal strengths compatible with the Standard Model prediction. Measurements of simplified template cross sections, designed to quantify the different Higgs boson production processes in specific regions of phase space, are reported. The cross section for the production of the Higgs boson decaying to two isolated photons in a fiducial region closely matching the experimental selection of the photons is measured to be $55 \pm 10$ fb, which is in good agreement with the Standard Model prediction of $64 \pm 2$ fb. Furthermore, cross sections in fiducial regions enriched in Higgs boson production in vector-boson fusion or in association with large missing transverse momentum, leptons or top-quark pairs are reported. Differential and double-differential measurements are performed for several variables related to the diphoton kinematics as well as the kinematics and multiplicity of the jets produced in association with a Higgs boson. No significant deviations from a wide array of Standard Model predictions are observed.
Measured differential cross section with associated uncertainties as a function of PT(2GAMMA). Each systematic uncertainty sources is fully uncorrelated with the other sources and fully correlated across bins, except for the background modelling systematics for which an uncorrelated treatment across bins is more appropriate.
Measured differential cross section with associated uncertainties as a function of YRAP(2GAMMA). Each systematic uncertainty sources is fully uncorrelated with the other sources and fully correlated across bins, except for the background modelling systematics for which an uncorrelated treatment across bins is more appropriate.
Measured differential cross section with associated uncertainties as a function of PTTHRUST(2GAMMA). Each systematic uncertainty sources is fully uncorrelated with the other sources and fully correlated across bins, except for the background modelling systematics for which an uncorrelated treatment across bins is more appropriate.
A search for dark matter (DM) particles produced in association with a hadronically decaying vector boson is performed using $pp$ collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV corresponding to an integrated luminosity of 36.1 fb$^{-1}$, recorded by the ATLAS detector at the Large Hadron Collider. This analysis improves on previous searches for processes with hadronic decays of $W$ and $Z$ bosons in association with large missing transverse momentum (mono-$W/Z$ searches) due to the larger dataset and further optimization of the event selection and signal region definitions. In addition to the mono-$W/Z$ search, the as yet unexplored hypothesis of a new vector boson $Z^\prime$ produced in association with dark matter is considered (mono-$Z^\prime$ search). No significant excess over the Standard Model prediction is observed. The results of the mono-$W/Z$ search are interpreted in terms of limits on invisible Higgs boson decays into dark matter particles, constraints on the parameter space of the simplified vector-mediator model and generic upper limits on the visible cross sections for $W/Z$+DM production. The results of the mono-$Z^\prime$ search are shown in the framework of several simplified-model scenarios involving DM production in association with the $Z^\prime$ boson.
The product of the acceptance and effifiency. Defined as the number of signal events satisfying the full set of selection criteria, divided by the total number of generated signal events, after the full event selection for the combined mono-W and mono-Z signal of the simplified vector-mediator model, shown in dependence on mass of the Z' mediator (mZp). For a given model, the signal contributions from each category are summed together.
The product of the acceptance and effifiency. Defined as the number of signal events satisfying the full set of selection criteria, divided by the total number of generated signal events, after the full event selection for the mono-Z' dark fermion and dark-Higgs signal models, shown in dependence on the mass of the Z' mediator (mZp). For a given model, the signal contributions from each category are summed together.
The observed and expected MET distributions with 36.1fb-1 of data with sqrt(s) = 13 TeV in the mono-W/Z signal region with the merged event topology after the profile-likelihood fit. This is shown for the 0b-tagged jet, high purity, event category.
A search for new charged massive gauge bosons, $W^\prime$, is performed with the ATLAS detector at the LHC. Data were collected in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV and correspond to an integrated luminosity of 36.1 $\textrm{fb}^{-1}$. This analysis searches for $W^\prime$ bosons in the $W^\prime \rightarrow t\bar{b}$ decay channel in final states with an electron or muon plus jets. The search covers resonance masses between 0.5 and 5.0 TeV and considers right-handed $W^\prime$ bosons. No significant deviation from the Standard Model (SM) expectation is observed and upper limits are set on the $W^\prime \rightarrow t\bar{b}$ cross section times branching ratio and the $W^\prime$ boson effective couplings as a function of the $W^\prime$ boson mass. For right-handed $W^\prime$ bosons with coupling to the SM particles equal to the SM weak coupling constant, masses below 3.15 TeV are excluded at the 95% confidence level. This search is also combined with a previously published ATLAS result for $W^\prime \rightarrow t\bar{b}$ in the fully hadronic final state. Using the combined searches, right-handed $W^\prime$ bosons with masses below 3.25 TeV are excluded at the 95% confidence level.
Signal selection efficiency (efficiency is defined as the number of events passing all selections divided by the total number of simulated $W' \to t\bar{b} \to \ell \nu b \bar{b}$ events) in the signal region as a function of the simulated $W^\prime_{\textrm{R}}$ mass.
Distribution of the reconstructed invariant mass of the $W^\prime$ boson candidate in the 2-jet 1-tag VR$_{\textrm{HF}}$ electron validation region. Background templates are fit to data in each VR using the same statistical method as for the signal region except that the normalizations of $t\bar{t}$ and $W$+jets backgrounds are constrained to the post-fit rates obtained in the signal region. Uncertainties include all the systematic and statistical uncertainties.
Distribution of the reconstructed invariant mass of the $W^\prime$ boson candidate in the 2-jet 1-tag VR$_{\textrm{HF}}$ muon validation region. Background templates are fit to data in each VR using the same statistical method as for the signal region except that the normalizations of $t\bar{t}$ and $W$+jets backgrounds are constrained to the post-fit rates obtained in the signal region. Uncertainties include all the systematic and statistical uncertainties.
A search for new phenomena in events with two same-charge leptons or three leptons and jets identified as originating from $b$-quarks in a data sample of 36.1 fb$^{-1}$ of $pp$ collisions at $\sqrt{s}= 13$ TeV recorded by the ATLAS detector at the Large Hadron Collider is reported. No significant excess is found and limits are set on vector-like quark, four-top-quark, and same-sign top-quark pair production. The observed (expected) 95% CL mass limits for a vector-like $T$- and $B$-quark singlet are $m_T > 0.98$ $(0.99)$ TeV and $m_B > 1.00$ $(1.01)$ TeV respectively. Limits on the production of the vector-like $T_{5/3}$-quark are also derived considering both pair and single production; in the former case the lower limit on the mass of the $T_{5/3}$-quark is (expected to be) 1.19 (1.21) TeV. The Standard Model four-top-quark production cross-section upper limit is (expected to be) 69 (29) fb. Constraints are also set on exotic four-top-quark production models. Finally, limits are set on same-sign top-quark pair production. The upper limit on $uu \to tt$ production is (expected to be) 89 (59) fb for a mediator mass of 1 TeV, and a dark-matter interpretation is also derived, excluding a mediator of 3 TeV with a dark-sector coupling of 1.0 and a coupling to ordinary matter above 0.31.
Expected and observed limits on vector-like B-quark pair production as a function of mass, assuming the branching ratios expected in the singlet model.
Expected and observed limits on vector-like B-quark pair production as a function of mass, assuming the branching ratios expected in the singlet model.
Expected and observed limits on vector-like T-quark pair production as a function of mass, assuming the branching ratios expected in the singlet model.
Charged-particle distributions are measured in proton-proton collisions at a centre-of-mass energy of 13 TeV, using a data sample of nearly 9 million events, corresponding to an integrated luminosity of 170 $\mu$b$^{-1}$, recorded by the ATLAS detector during a special Large Hadron Collider fill. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the dependence of the mean transverse momentum on the charged-particle multiplicity are presented. The measurements are performed with charged particles with transverse momentum greater than 500 MeV and absolute pseudorapidity less than 2.5, in events with at least one charged particle satisfying these kinematic requirements. Additional measurements in a reduced phase space with absolute pseudorapidity less than 0.8 are also presented, in order to compare with other experiments. The results are corrected for detector effects, presented as particle-level distributions and are compared to the predictions of various Monte Carlo event generators.
The average charged-particle multiplicity per unit of rapidity for ETARAP=0 as a function of the centre-of-mass energy.
The extrapolated average charged-particle multiplicity per unit of rapidity for ETARAP=0 as a function of the centre-of-mass energy.
Charged-particle multiplicities in proton-proton collisions at a centre-of-mass energy of 13000 GeV as a function of pseudorapidity for events with the number of charged particles >=1 having transverse momentum >500 MeV and absolute(pseudorapidity) <2.5.
Results are reported of a search for new phenomena, such as supersymmetric particle production, that could be observed in high-energy proton--proton collisions. Events with large numbers of jets, together with missing transverse momentum from unobserved particles, are selected. The data analysed were recorded by the ATLAS experiment during 2015 using the 13 TeV centre-of-mass proton--proton collisions at the Large Hadron Collider, and correspond to an integrated luminosity of 3.2 fb$^{-1}$. The search selected events with various jet multiplicities from $\ge 7$ to $\ge 10$ jets, and with various $b$-jet multiplicity requirements to enhance sensitivity. No excess above Standard Model expectations is observed. The results are interpreted within two supersymmetry models, where gluino masses up to 1400 GeV are excluded at 95% confidence level, significantly extending previous limits.
$E_{\mathrm{T}}^{\mathrm{miss}} / \sqrt{H_{\mathrm{T}}}$ distribution in validation region 7ej50 0b. Two benchmark signal models are overlaid on the plot for comparison. Labelled `pMSSM' and `2-step', they show signal distributions from the example SUSY models (as described in the paper): a pMSSM slice model with ($m \tilde{g}$, $m \tilde{\chi_{1}^{\pm}}$) = (1300, 200) GeV and a cascade decay model with ($m \tilde{g}$, $m \tilde{\chi_{1}^{0}}$) = (1300, 200) GeV.
$E_{\mathrm{T}}^{\mathrm{miss}} / \sqrt{H_{\mathrm{T}}}$ distribution in validation region 6ej80 0b. Two benchmark signal models are overlaid on the plot for comparison. Labelled `pMSSM' and `2-step', they show signal distributions from the example SUSY models (as described in the paper): a pMSSM slice model with ($m \tilde{g}$, $m \tilde{\chi_{1}^{\pm}}$) = (1300, 200) GeV and a cascade decay model with ($m \tilde{g}$, $m \tilde{\chi_{1}^{0}}$) = (1300, 200) GeV.
$E_{\mathrm{T}}^{\mathrm{miss}} / \sqrt{H_{\mathrm{T}}}$ distribution in signal region 10j50 0b. Two benchmark signal models are overlaid on the plot for comparison. Labelled `pMSSM' and `2-step', they show signal distributions from the example SUSY models (as described in the paper): a pMSSM slice model with ($m \tilde{g}$, $m \tilde{\chi_{1}^{\pm}}$) = (1300, 200) GeV and a cascade decay model with ($m \tilde{g}$, $m \tilde{\chi_{1}^{0}}$) = (1300, 200) GeV.
The $ZZ$ production cross section in proton-proton collisions at 13 TeV center-of-mass energy is measured using 3.2 fb$^{-1}$ of data recorded with the ATLAS detector at the Large Hadron Collider. The considered $Z$ boson candidates decay to an electron or muon pair of mass 66-116 GeV. The cross section is measured in a fiducial phase space reflecting the detector acceptance. It is also extrapolated to a total phase space for $Z$ bosons in the same mass range and of all decay modes, giving $16.7^{+2.2}_{-2.0}$(stat.)$^{+0.9}_{-0.7}$(syst.)$^{+1.0}_{-0.7}$(lumi.) pb. The results agree with standard model predictions.
Measured fiducial cross section in the $e^+e^-e^+e^-$ channel. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity uncertainty, the second is the luminosity uncertainty.
Measured fiducial cross section in the $e^+e^-\mu^+\mu^-$ channel. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity uncertainty, the second is the luminosity uncertainty.
Measured fiducial cross section in the $\mu^+\mu^-\mu^+\mu^-$ channel. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity uncertainty, the second is the luminosity uncertainty.
The cross-section for the production of two jets in association with a leptonically decaying Z boson ($Zjj$) is measured in proton-proton collisions at a centre-of-mass energy of 13 TeV, using data recorded with the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 3.2 fb$^{-1}$. The electroweak $Zjj$ cross-section is extracted in a fiducial region chosen to enhance the electroweak contribution relative to the dominant Drell-Yan $Zjj$ process, which is constrained using a data-driven approach. The measured fiducial electroweak cross-section is $\sigma^{Zjj}_{EW}= 119\pm 16 (\mathrm{stat.}) \pm 20 (\mathrm{syst.})\pm 2 (\mathrm{lumi.})$ for dijet invariant mass greater than 250 GeV, and $34.2\pm 5.8 (\mathrm{stat.})\pm 5.5 (\mathrm{syst.})\pm 0.7 (\mathrm{lumi.})$ for dijet invariant mass greater than 1 TeV. Standard Model predictions are in agreement with the measurements. The inclusive $Zjj$ cross-section is also measured in six different fiducial regions with varying contributions from electroweak and Drell-Yan $Zjj$ production.
Fiducial regions definitions
Measured and predicted inclusive Zjj production cross-sections in the six fiducial regions
Measured and predicted EW-Zjj production cross-sections in the EW-enriched fiducial regions with and without an additional kinematic requirement of $m_{jj} > $ 1 TeV
The results of a search for vector-like top quarks using events with exactly one lepton, at least four jets, and large missing transverse momentum are reported. The search is optimised for pair production of vector-like top quarks in the $Z(\rightarrow \! \! \nu \nu) \, t + X$ decay channel. LHC pp collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV recorded by the ATLAS detector in 2015 and 2016 are used, corresponding to an integrated luminosity of 36.1 $\mathrm{fb}^{-1}$. No significant excess over the Standard Model expectation is seen and upper limits on the production cross-section of a vector-like $T$ quark pair as a function of the $T$ quark mass are derived. The observed (expected) 95% CL lower limits on the $T$ mass are 870 GeV (890 GeV) for the weak-isospin singlet model, 1.05 TeV (1.06 TeV) for the weak-isospin doublet model and 1.16 TeV (1.17 TeV) for the pure $Zt$ decay mode. Limits are also set on the mass as a function of the decay branching ratios, excluding large parts of the parameter space for masses below 1 TeV.
Expected and observed 95% CL upper limit on the cross-section times branching ratio for VLQ $T$ pair production as a function of the $T$ mass for BR($T \rightarrow Zt$) = 100%.
Expected and observed 95% CL upper limit on the cross-section times branching ratio for VLQ $T$ pair production as a function of the $T$ mass for branching ratios according to the singlet model.
Expected and observed 95% CL upper limit on the cross-section times branching ratio for VLQ $T$ pair production as a function of the $T$ mass for branching ratios according to the doublet model. Contributions from the $X$ or $B$ quark in the $(X^{5/3}, T)$ or $(T, B)$ doublet models are neglected, leading to very conservative limits.
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