The fragmentation properties of jets containing $b$-hadrons are studied using charged $B$ mesons in 139 fb$^{-1}$ of $pp$ collisions at $\sqrt{s} = 13$ TeV, recorded with the ATLAS detector at the LHC during the period from 2015 to 2018. The $B$ mesons are reconstructed using the decay of $B^{\pm}$ into $J/\psi K^{\pm}$, with the $J/\psi$ decaying into a pair of muons. Jets are reconstructed using the anti-$k_t$ algorithm with radius parameter $R=0.4$. The measurement determines the longitudinal and transverse momentum profiles of the reconstructed $B$ hadrons with respect to the axes of the jets to which they are geometrically associated. These distributions are measured in intervals of the jet transverse momentum, ranging from 50 GeV to above 100 GeV. The results are corrected for detector effects and compared with several Monte Carlo predictions using different parton shower and hadronisation models. The results for the longitudinal and transverse profiles provide useful inputs to improve the description of heavy-flavour fragmentation in jets.
Longitudinal profile for 50 GeV < pT < 70 GeV.
Transverse profile for 50 GeV < pT < 70 GeV.
Longitudinal profile for 70 GeV < pT < 100 GeV.
A measurement of the top-quark mass ($m_t$) in the $t\bar{t}\rightarrow~\textrm{lepton}+\textrm{jets}$ channel is presented, with an experimental technique which exploits semileptonic decays of $b$-hadrons produced in the top-quark decay chain. The distribution of the invariant mass $m_{\ell\mu}$ of the lepton, $\ell$ (with $\ell=e,\mu$), from the $W$-boson decay and the muon, $\mu$, originating from the $b$-hadron decay is reconstructed, and a binned-template profile likelihood fit is performed to extract $m_t$. The measurement is based on data corresponding to an integrated luminosity of 36.1 fb$^{-1}$ of $\sqrt{s} = 13~\textrm{TeV}$$pp$ collisions provided by the Large Hadron Collider and recorded by the ATLAS detector. The measured value of the top-quark mass is $m_{t} = 174.41\pm0.39~(\textrm{stat.})\pm0.66~(\textrm{syst.})\pm0.25~(\textrm{recoil})~\textrm{GeV}$, where the third uncertainty arises from changing the PYTHIA8 parton shower gluon-recoil scheme, used in top-quark decays, to a recently developed setup.
Top mass measurement result.
List of all the individual sources of systematic uncertainty considered in the analysis. The individual sources, each corresponding to an independent nuisance parameter in the fit, are grouped into categories, as indicated in the first column. The second column shows the impact of each of the individual sources on the measurement, obtained as the shift on the top mass induced by a positive shift of the each of the nuisance parameters by its post-fit uncertainty. Sources for which no impact is indicated are neglected in the fit procedure as their impact on the total prediction is negligible in any of the bins. The last column shows the statistical uncertainty in each of the reported numbers as estimated with the bootstrap method.
Ranking, from top to bottom, of the main systematic uncertainties (excluding recoil) showing the pulls and the impact of the systematic uncertainties on the top mass, from the combined opposite sign (OS) and same sign (SS) binned-template profile likelihood fit to data. The OS or SS refers to the charge signs of the primary lepton and the soft muon. The gamma parameters are NPs used to describe the effect of the limited statistics of the sample.
This paper presents a measurement of the electroweak production of two jets in association with a $Z\gamma$ pair, with the $Z$ boson decaying into two neutrinos. It also presents a search for invisible or partially invisible decays of a Higgs boson with a mass of 125 GeV produced through vector-boson fusion with a photon in the final state. These results use data from LHC proton-proton collisions at $\sqrt{s}$ = 13 TeV collected with the ATLAS detector and corresponding to an integrated luminosity of 139 fb$^{-1}$. The event signature, shared by all benchmark processes considered for the measurements and searches, is characterized by a significant amount of unbalanced transverse momentum and a photon in the final state, in addition to a pair of forward jets. Electroweak $Z\gamma$ production in association with two jets is observed in this final state with a significance of 5.2 (5.1 expected) standard deviations. The measured fiducial cross-section for this process is 1.31$\pm$0.29 fb. An observed (expected) upper limit of 0.37 ($0.34^{+0.15}_{-0.10}$) at 95% confidence level is set on the branching ratio of a 125 GeV Higgs boson to invisible particles, assuming the Standard Model production cross-section. The signature is also interpreted in the context of decays of a Higgs boson into a photon and a dark photon. An observed (expected) 95% CL upper limit on the branching ratio for this decay is set at 0.018 ($0.017^{+0.007}_{-0.005}$), assuming the Standard Model production cross-section for a 125 GeV Higgs boson.
Post-fit results for all $m_\text{jj}$ SR and CR bins in the EW $Z \gamma + \text{jets}$ cross-section measurement with the $\mu_{Z \gamma_\text{EW}}$ signal normalization floating. The post-fit uncertainties include statistical, experimental, and theory contributions.
Post-fit results for all DNN SR and CR bins in the search for $H \to \text{inv.}$ with the $\mathcal{B}_\text{inv}$ signal normalization set to zero. For the $Z_\text{Rev.Cen.}^\gamma$ CR, the third bin contains all events with DNN output score values of 0.6-1.0. The $H \to \text{inv.}$ signal is scaled to a $\mathcal{B}_\text{inv}$ of 37%. The post-fit uncertainties include statistical, experimental, and theoretical contributions.
Post-fit results for the ten [$m_\text{jj}$, $m_\text{T}$] bins constituting the SR and CRs defined for the dark photon search with the $\mathcal{B}(H \to \gamma \gamma_\text{d})$ signal normalization set to zero. A $H \to \gamma \gamma_\text{d}$ signal is shown for two different mass hypotheses (125 GeV, 500 GeV) and scaled to a branching ratio of 2% and 1%, respectively. The post-fit uncertainties include statistical, experimental, and theoretical contributions.
A measurement of prompt photon-pair production in proton-proton collisions at $\sqrt{s}=13$ TeV is presented. The data were recorded by the ATLAS detector at the LHC with an integrated luminosity of 139 fb$^{-1}$. Events with two photons in the well-instrumented region of the detector are selected. The photons are required to be isolated and have a transverse momentum of $p_\mathrm{T,\gamma_{1(2)}} > 40(30)$ GeV for the leading (sub-leading) photon. The differential cross sections as functions of several observables for the diphoton system are measured and compared with theoretical predictions from state-of-the-art Monte Carlo and fixed-order calculations. The QCD predictions from next-to-next-to-leading-order calculations and multi-leg merged calculations are able to describe the measured integrated and differential cross sections within uncertainties, whereas lower-order calculations show significant deviations, demonstrating that higher-order perturbative QCD corrections are crucial for this process. The resummed predictions with parton showers additionally provide an excellent description of the low transverse-momentum regime of the diphoton system.
Differential cross section as a function of $p_{T,\gamma_{1}}$. The table contains the values measured in data and theory predictions from SHERPA, DIPHOX and NNLOJET.
Differential cross section as a function of $p_{T,\gamma_{2}}$. The table contains the values measured in data and theory predictions from SHERPA, DIPHOX and NNLOJET.
Integrated fiducial cross section measured in data and from different predictions.
A measurement of four-top-quark production using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider corresponding to an integrated luminosity of 139 fb$^{-1}$ is presented. Events are selected if they contain a single lepton (electron or muon) or an opposite-sign lepton pair, in association with multiple jets. The events are categorised according to the number of jets and how likely these are to contain $b$-hadrons. A multivariate technique is then used to discriminate between signal and background events. The measured four-top-quark production cross section is found to be 26$^{+17}_{-15}$ fb, with a corresponding observed (expected) significance of 1.9 (1.0) standard deviations over the background-only hypothesis. The result is combined with the previous measurement performed by the ATLAS Collaboration in the multilepton final state. The combined four-top-quark production cross section is measured to be 24$^{+7}_{-6}$ fb, with a corresponding observed (expected) signal significance of 4.7 (2.6) standard deviations over the background-only predictions. It is consistent within 2.0 standard deviations with the Standard Model expectation of 12.0$\pm$2.4 fb.
The results of the fitted signal strength $\mu$ in the 1L/2LOS channel
The results of fitted inclusive ${t\bar{t}t\bar{t}}$ cross-section in the 1L/2LOS channel
Ranking of the nuisance parameters included in the fit according to their impact on the signal strength $\mu$. The impact of each nuisance parameter, $\Delta\mu$, is computed by comparing the nominal best-fit value of $\mu$ with the result of the fit when fixing the nuisance parameter to its best-fit value, $\hat{\theta}$, shifted by its pre-fit (post-fit) uncertainties $\pm \Delta\theta$ ($\pm \Delta\hat{\theta}$).
A search for the pair production of heavy leptons as predicted by the type-III seesaw mechanism is presented. The search uses proton-proton collision data at a centre-of-mass energy of 13 TeV, corresponding to 139 fb$^{-1}$ of integrated luminosity recorded by the ATLAS detector during Run 2 of the Large Hadron Collider. The analysis focuses on final states with three or four electrons or muons from the possible decays of new heavy leptons via intermediate electroweak bosons. No significant deviations above the Standard Model expectation are observed; upper and lower limits on the heavy lepton production cross-section and masses are derived respectively. These results are then combined for the first time with the ones already published by ATLAS using the channel with two leptons in the final state. The observed lower limit on the mass of the type-III seesaw heavy leptons combining two, three and four lepton channels together is 910 GeV at the 95% confidence level.
Expected background yields and observed data after the background-only fit in the SRs.
Distribution of $m_{\mathrm{T},3l}$ in the ZL SR after the background-only fit. The uncertainty on the expected number of background events includes all statistical and systematic post-fit uncertainties with the correlations between various background sources taken into account.
Distribution of $m_{\mathrm{T},3l}$ in the ZL Veto SR after the background-only fit. The uncertainty on the expected number of background events includes all statistical and systematic post-fit uncertainties with the correlations between various background sources taken into account.
A search for the exotic decay of the Higgs boson ($H$) into a $b\bar{b}$ resonance plus missing transverse momentum is described. The search is performed with the ATLAS detector at the Large Hadron Collider using 139 $\mathrm{fb}^{-1}$ of $pp$ collisions at $\sqrt{s} = 13$ TeV. The search targets events from $ZH$ production in an NMSSM scenario where $H \rightarrow \tilde{\chi}^{0}_{2}\tilde{\chi}^{0}_{1}$, with $\tilde{\chi}^{0}_{2} \rightarrow {a} \tilde{\chi}^{0}_{1}$, where $a$ is a light pseudoscalar Higgs boson and $\tilde{\chi}^{0}_{1,2}$ are the two lightest neutralinos. The decay of the $a$ boson into a pair of $b$-quarks results in a peak in the dijet invariant mass distribution. The final-state signature consists of two leptons, two or more jets, at least one of which is identified as originating from a $b$-quark, and missing transverse momentum. Observations are consistent with Standard Model expectations and upper limits are set on the product of cross section times branching ratio for a three-dimensional scan of the masses of the $\tilde{\chi}^{0}_{2}$, $\tilde{\chi}^{0}_{1}$ and $a$ boson.
Distribution of the dijet invariant mass in CRZ. The Z+HF and $t\bar{t}$ scale factors, described in the text, have been applied to the simulated samples. The distribution labeled "Signal" is for the model with ($m_a$, $m_{\tilde{\chi}_{1}^{0}}$, $m_{\tilde{\chi}_{2}^{0}}$) = (45 GeV, 10 GeV, 80 GeV).
Distribution of the missing transverse energy in VRMET. The Z+HF and $t\bar{t}$ scale factors, described in the text, have been applied to the simulated samples. The distribution labeled "Signal" is for the model with ($m_a$, $m_{\tilde{\chi}_{1}^{0}}$, $m_{\tilde{\chi}_{2}^{0}}$) = (45 GeV, 10 GeV, 80 GeV).
Distribution of the dijet invariant mass in CRTop. The Z+HF and $t\bar{t}$ scale factors, described in the text, have been applied to the simulated samples. The distribution labeled "Signal" is for the model with ($m_a$, $m_{\tilde{\chi}_{1}^{0}}$, $m_{\tilde{\chi}_{2}^{0}}$) = (45 GeV, 10 GeV, 80 GeV).
The production of dark matter in association with Higgs bosons is predicted in several extensions of the Standard Model. An exploration of such scenarios is presented, considering final states with missing transverse momentum and $b$-tagged jets consistent with a Higgs boson. The analysis uses proton-proton collision data at a centre-of-mass energy of 13 TeV recorded by the ATLAS experiment at the LHC during Run 2, amounting to an integrated luminosity of 139 fb$^{-1}$. The analysis, when compared with previous searches, benefits from a larger dataset, but also has further improvements providing sensitivity to a wider spectrum of signal scenarios. These improvements include both an optimised event selection and advances in the object identification, such as the use of the likelihood-based significance of the missing transverse momentum and variable-radius track-jets. No significant deviation from Standard Model expectations is observed. Limits are set, at 95% confidence level, in two benchmark models with two Higgs doublets extended by either a heavy vector boson $Z'$ or a pseudoscalar singlet $a$ and which both provide a dark matter candidate $\chi$. In the case of the two-Higgs-doublet model with an additional vector boson $Z'$, the observed limits extend up to a $Z'$ mass of 3 TeV for a mass of 100 GeV for the dark matter candidate. The two-Higgs-doublet model with a dark matter particle mass of 10 GeV and an additional pseudoscalar $a$ is excluded for masses of the $a$ up to 520 GeV and 240 GeV for $\tan \beta = 1$ and $\tan \beta = 10$ respectively. Limits on the visible cross-sections are set and range from 0.05 fb to 3.26 fb, depending on the missing transverse momentum and $b$-quark jet multiplicity requirements.
<b>- - - - - - - - Overview of HEPData Record - - - - - - - -</b> <br><br> <b>Exclusion contours:</b> <ul> <li><a href="?table=LimitContour_ZP2HDM_obs">Observed 95% CL exclusion limit for the Z'-2HDM model</a> <li><a href="?table=LimitContour_ZP2HDM_exp">Expected 95% CL exclusion limit for the Z'-2HDM model</a> <li><a href="?table=LimitContour_ZP2HDM_exp_1s">Expected +- 1sigma 95% CL exclusion limit for the Z'-2HDM model</a> <li><a href="?table=LimitContour_ZP2HDM_exp_2s">Expected +- 2sigma 95% CL exclusion limit for the Z'-2HDM model</a> <li><a href="?table=LimitContour_2HDMa_tb1_sp0p35_obs">Observed 95% CL exclusion limit for ggF production in the 2HDM+a model</a> <li><a href="?table=LimitContour_2HDMa_tb1_sp0p35_exp">Expected 95% CL exclusion limit for ggF production in the 2HDM+a model</a> <li><a href="?table=LimitContour_2HDMa_tb1_sp0p35_exp_1s">Expected +- 1 sigma 95% CL exclusion limit for ggF production in the 2HDM+a model</a> <li><a href="?table=LimitContour_2HDMa_tb1_sp0p35_exp_2s">Expected +- 2 sigma 95% CL exclusion limit for ggF production in the 2HDM+a model</a> <li><a href="?table=LimitContour_2HDMa_tb10_sp0p35_obs">Observed 95% CL exclusion limit for bbA production in the 2HDM+a model</a> <li><a href="?table=LimitContour_2HDMa_tb10_sp0p35_exp">Expected 95% CL exclusion limit for bbA production in the 2HDM+a model</a> <li><a href="?table=LimitContour_2HDMa_tb10_sp0p35_exp_1s">Expected +- 1 sigma 95% CL exclusion limit for bbA production in the 2HDM+a model</a> <li><a href="?table=LimitContour_2HDMa_tb10_sp0p35_exp_2s">Expected +- 2 sigma 95% CL exclusion limit for bbA production in the 2HDM+a model</a> <li><a href="?table=LimitContour_ZP2HDM_2018CONF_obs">Observed 95% CL exclusion limit for the Z'-2HDM model with the benchmark used in arXiv:1707.01302.</a> <li><a href="?table=LimitContour_ZP2HDM_2018CONF_exp">Expected 95% CL exclusion limit for the Z'-2HDM model with the benchmark used in arXiv:1707.01302.</a> <li><a href="?table=LimitContour_ZP2HDM_2018CONF_exp_1s">Expected +- 1 sigma 95% CL exclusion limit for the Z'-2HDM model with the benchmark used in arXiv:1707.01302.</a> <li><a href="?table=LimitContour_ZP2HDM_2018CONF_exp_2s">Expected +- 2 sigma 95% CL exclusion limit for the Z'-2HDM model with the benchmark used in arXiv:1707.01302.</a> </ul> <b>Upper limits on cross-sections:</b> <ul> <li><a href="?table=Limits_ZP2HDM">95% CL upper limit on the cross-section for the Z'-2HDM model</a> <li><a href="?table=Limits_2HDMa_tb1_sp0p35">95% CL upper limit on the ggF cross-section in the 2HDM+a model</a> <li><a href="?table=Limits_2HDMa_tb10_sp0p35">95% CL upper limit on the bbA cross-section in the 2HDM+a model</a> <li><a href="?table=MIL">95% CL upper limit on the visible cross-section</a> </ul> <b>Theoretical cross-sections:</b> <ul> <li><a href="?table=CrossSections_ZP2HDM">Cross-section for the Z'-2HDM model</a> <li><a href="?table=CrossSections_2HDMa_tb1_sp0p35">Cross-section for ggF production in the 2HDM+a model</a> <li><a href="?table=CrossSections_2HDMa_tb10_sp0p35">Cross-section for bbA production in the 2HDM+a model</a> </ul> <b>Kinematic distributions:</b> <ul> <li><a href="?table=SR_post_plot_2b_150_200">Higgs candidate invariant mass in the region with 2 b-jets and missing energy between 150-200 GeV</a> <li><a href="?table=SR_post_plot_2b_200_350">Higgs candidate invariant mass in the region with 2 b-jets and missing energy between 200-350 GeV</a> <li><a href="?table=SR_post_plot_2b_350_500">Higgs candidate invariant mass in the region with 2 b-jets and missing energy between 350-500 GeV</a> <li><a href="?table=SR_post_plot_2b_500_750">Higgs candidate invariant mass in the region with 2 b-jets and missing energy between 500-750 GeV</a> <li><a href="?table=SR_post_plot_2b_750">Higgs candidate invariant mass in the region with 2 b-jets and missing energy higher than 750 GeV</a> <li><a href="?table=SR_post_plot_3b_150_200">Higgs candidate invariant mass in the region with at least 3 b-jets and missing energy between 150-200 GeV</a> <li><a href="?table=SR_post_plot_3b_200_350">Higgs candidate invariant mass in the region with at least 3 b-jets and missing energy between 200-350 GeV</a> <li><a href="?table=SR_post_plot_3b_350_500">Higgs candidate invariant mass in the region with at least 3 b-jets and missing energy between 350-500 GeV</a> <li><a href="?table=SR_post_plot_3b_500">Higgs candidate invariant mass in the region with at least 3 b-jets and missing energy higher than 500 GeV</a> <li><a href="?table=MET_post_plot_0L2b">Missing energy in events with 0 leptons and 2 b-jets</a> <li><a href="?table=MET_post_plot_0L3b">Missing energy in events with 0 leptons and at least 3 b-jets</a> <li><a href="?table=CR_post_plot_CR1">Yields in the different missing energy bins and muon-charge of the 1-lepton control region</a> <li><a href="?table=CR_post_plot_CR2">Yields in the different METlepInv bins of the 2-lepton control region</a> </ul> <b>Cut flows:</b> The tables contain three columns, corresponding to the Z'-2HDM and 2HDM+a model assuming 100% ggF or bbA production respectively. <ul> <li><a href="?table=Resolved_150_200_2b">Signal region with 2 b-jets and missing energy between 150-200 GeV</a> <li><a href="?table=Resolved_200_350_2b">Signal region with 2 b-jets and missing energy between 200-350 GeV</a> <li><a href="?table=Resolved_350_500_2b">Signal region with 2 b-jets and missing energy between 350-500 GeV</a> <li><a href="?table=Merged_500_750_2w0b">Signal region with 2 b-jets and missing energy between 500-750 GeV</a> <li><a href="?table=Merged_750_2w0b">Signal region with 2 b-jets and missing energy higher than 750 GeV</a> <li><a href="?table=Resolved_150_200_3pb">Signal region with at least 3 b-jets and missing energy between 150-200 GeV</a> <li><a href="?table=Resolved_200_350_3pb">Signal region with at least 3 b-jets and missing energy between 200-350 GeV</a> <li><a href="?table=Resolved_350_500_3pb">Signal region with at least 3 b-jets and missing energy between 350-500 GeV</a> <li><a href="?table=Merged_2w1pb">Signal region with at least 3 b-jets and missing energy higher than 500 GeV</a> </ul> <b>Acceptance and efficiencies:</b> <ul> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_bb_2_150_noHiggsWindowCut">2HDM+a model, bbA production, 2 b-jets, MET=150-200 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_bb_2_200_noHiggsWindowCut">2HDM+a model, bbA production, 2 b-jets, MET=200-350 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_bb_2_350_noHiggsWindowCut">2HDM+a model, bbA production, 2 b-jets, MET=350-500 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_bb_2_500_noHiggsWindowCut">2HDM+a model, bbA production, 2 b-jets, MET=500-750 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_bb_2_750ptv_noHiggsWindowCut">2HDM+a model, bbA production, 2 b-jets, MET higher than 750 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_bb_3_150_noHiggsWindowCut">2HDM+a model, bbA production, at least 3 b-jets, MET=150-200 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_bb_3_200_noHiggsWindowCut">2HDM+a model, bbA production, at least 3 b-jets, MET=200-350 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_bb_3_350_noHiggsWindowCut">2HDM+a model, bbA production, at least 3 b-jets, MET=350-500 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_bb_3_500ptv_noHiggsWindowCut">2HDM+a model, bbA production, at least 3 b-jets, MET higher than GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_ggF_2_150_noHiggsWindowCut">2HDM+a model, ggF production, 2 b-jets, MET=150-200 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_ggF_2_200_noHiggsWindowCut">2HDM+a model, ggF production, 2 b-jets, MET=200-350 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_ggF_2_350_noHiggsWindowCut">2HDM+a model, ggF production, 2 b-jets, MET=350-500 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_ggF_2_500_noHiggsWindowCut">2HDM+a model, ggF production, 2 b-jets, MET=500-750 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_ggF_2_750ptv_noHiggsWindowCut">2HDM+a model, ggF production, 2 b-jets, MET higher than 750 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_ggF_3_150_noHiggsWindowCut">2HDM+a model, ggF production, at least 3 b-jets, MET=150-200 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_ggF_3_200_noHiggsWindowCut">2HDM+a model, ggF production, at least 3 b-jets, MET=200-350 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_ggF_3_350_noHiggsWindowCut">2HDM+a model, ggF production, at least 3 b-jets, MET=350-500 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_a2HDM_ggF_3_500ptv_noHiggsWindowCut">2HDM+a model, ggF production, at least 3 b-jets, MET higher than 500 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_zp2hdm_CMS_2_150_noHiggsWindowCut">Z'-2HDM model, 2 b-jets, MET=150-200 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_zp2hdm_CMS_2_200_noHiggsWindowCut">Z'-2HDM model, 2 b-jets, MET=200-350 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_zp2hdm_CMS_2_350_noHiggsWindowCut">Z'-2HDM model, 2 b-jets, MET=350-500 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_zp2hdm_CMS_2_500_noHiggsWindowCut">Z'-2HDM model, 2 b-jets, MET=500-750 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_zp2hdm_CMS_2_750ptv_noHiggsWindowCut">Z'-2HDM model, 2 b-jets, MET higher than 750 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_zp2hdm_CMS_3_150_noHiggsWindowCut">Z'-2HDM model, at least 3 b-jets, MET=150-200 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_zp2hdm_CMS_3_200_noHiggsWindowCut">Z'-2HDM model, at least 3 b-jets, MET=200-350 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_zp2hdm_CMS_3_350_noHiggsWindowCut">Z'-2HDM model, at least 3 b-jets, MET=350-500 GeV</a> <li><a href="?table=AcceptanceTimesEfficiency_zp2hdm_CMS_3_500ptv_noHiggsWindowCut">Z'-2HDM model, at least 3 b-jets, MET higher than 500 GeV</a> </ul>
Observed 95% CL exclusion limit for the Zprime-2HDM model.
Expected 95% CL exclusion limit for the Zprime-2HDM model.
A search for R-parity violating supersymmetry in final states characterised by high jet multiplicity, at least one isolated light lepton and either zero or at least three $b$-tagged jets is presented. The search uses 139 fb$^{-1}$ of $\sqrt{s} = 13$ TeV proton-proton collision data collected by the ATLAS experiment during Run 2 of the Large Hadron Collider. The results are interpreted in the context of R-parity-violating supersymmetry models that feature gluino production, top-squark production, or electroweakino production. The dominant sources of background are estimated using a data-driven model, based on observables at medium jet multiplicity, to predict the $b$-tagged jet multiplicity distribution at the higher jet multiplicities used in the search. Machine learning techniques are used to reach sensitivity to electroweakino production, extending the data-driven background estimation to the shape of the machine learning discriminant. No significant excess over the Standard Model expectation is observed and exclusion limits at the 95% confidence-level are extracted, reaching as high as 2.4 TeV in gluino mass, 1.35 TeV in top-squark mass, and 320 (365) GeV in higgsino (wino) mass.
The observed data event yields and the corresponding estimates for the backgrounds in the different $b$-jet multiplicity bins for the 20 GeV jet $p_{\mathrm{T}}$ threshold regions defined for the EWK analysis in the $1\ell$ category for 4 jets. The background is estimated by including all bins in the fit. All uncertainties, which may be correlated across the bins, are included in the total background uncertainty.
The observed data event yields and the corresponding estimates for the backgrounds in the different $b$-jet multiplicity bins for the 20 GeV jet $p_{\mathrm{T}}$ threshold regions defined for the EWK analysis in the $1\ell$ category for 5 jets. The background is estimated by including all bins in the fit. All uncertainties, which may be correlated across the bins, are included in the total background uncertainty.
The observed data event yields and the corresponding estimates for the backgrounds in the different $b$-jet multiplicity bins for the 20 GeV jet $p_{\mathrm{T}}$ threshold regions defined for the EWK analysis in the $1\ell$ category for 6 jets. The background is estimated by including all bins in the fit. All uncertainties, which may be correlated across the bins, are included in the total background uncertainty.
A search for heavy Higgs bosons produced in association with a vector boson and decaying into a pair of vector bosons is performed in final states with two leptons (electrons or muons) of the same electric charge, missing transverse momentum and jets. A data sample of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider between 2015 and 2018 is used. The data correspond to a total integrated luminosity of 139 fb$^{-1}$. The observed data are in agreement with Standard Model background expectations. The results are interpreted using higher-dimensional operators in an effective field theory. Upper limits on the production cross-section are calculated at 95% confidence level as a function of the heavy Higgs boson's mass and coupling strengths to vector bosons. Limits are set in the Higgs boson mass range from 300 to 1500 GeV, and depend on the assumed couplings. The highest excluded mass for a heavy Higgs boson with the coupling combinations explored is 900 GeV. Limits on coupling strengths are also provided.
Comparison between data and SM predictions for the meff distributions in the boosted SR. The background predictions are obtained through a background-only simultaneous fit and are shown as filled histograms. The entries in overflow are included in the last bin. The size of the combined statistical and systematic uncertainty for the sum of the fitted background is indicated by the hatched band. The ratio of the data to the sum of the fitted background is shown in the lower panel. Two benchmark signal samples, as indicated in the legend, are also shown as unstacked unfilled histograms normalised to the integrated luminosity of the data using the theoretical cross-sections.
Comparison between data and SM predictions for the meff distributions in the resolved SR. The background predictions are obtained through a background-only simultaneous fit and are shown as filled histograms. The entries in overflow are included in the last bin. The size of the combined statistical and systematic uncertainty for the sum of the fitted background is indicated by the hatched band. The ratio of the data to the sum of the fitted background is shown in the lower panel. Two benchmark signal samples, as indicated in the legend, are also shown as unstacked unfilled histograms normalised to the integrated luminosity of the data using the theoretical cross-sections.
Expected 95% CL upper limits on the production of a heavy Higgs boson as functions of fw and fww with mass equal to 300 GeV.
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