A search optimized for new heavy particles decaying to two $b$-quarks and produced in association with additional $b$-quarks is reported. The sensitivity is improved by $b$-tagging at least one lower-$p_{\rm{T}}$ jet in addition to the two highest-$p_{\rm{T}}$ jets. The data used in this search correspond to an integrated luminosity of 103 $\text{fb}^{-1}$ collected with a dedicated trijet trigger during the 2017 and 2018 $\sqrt{s} = 13$ TeV proton-proton collision runs with the ATLAS detector at the LHC. The search looks for resonant peaks in the $b$-tagged dijet invariant mass spectrum over a smoothly falling background. The background is estimated with an innovative data-driven method based on orthonormal functions. The observed $b$-tagged dijet invariant mass spectrum is compatible with the background-only hypothesis. Upper limits at 95% confidence level on a heavy vector-boson production cross section times branching ratio to a pair of $b$-quarks are derived.
Background estimate from the FD method with N=3 and data in the SR.
The observed (solid) and expected (dashed) 95% CL upper limits on the production of $Z' \to b\bar{b}$ in association with b-quarks.
Acceptance and Acceptance times efficiency for the LUV Z' model.
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.
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.
Heavy-flavour hadron production provides information about the transport properties and microscopic structure of the quark-gluon plasma created in ultra-relativistic heavy-ion collisions. A measurement of the muons from semileptonic decays of charm and bottom hadrons produced in Pb+Pb and $pp$ collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV with the ATLAS detector at the Large Hadron Collider is presented. The Pb+Pb data were collected in 2015 and 2018 with sampled integrated luminosities of $208~\mathrm{\mu b}^{-1}$ and $38~\mathrm{\mu b^{-1}}$, respectively, and $pp$ data with a sampled integrated luminosity of $1.17~\mathrm{pb}^{-1}$ were collected in 2017. Muons from heavy-flavour semileptonic decays are separated from the light-flavour hadronic background using the momentum imbalance between the inner detector and muon spectrometer measurements, and muons originating from charm and bottom decays are further separated via the muon track's transverse impact parameter. Differential yields in Pb+Pb collisions and differential cross sections in $pp$ collisions for such muons are measured as a function of muon transverse momentum from 4 GeV to 30 GeV in the absolute pseudorapidity interval $|\eta| < 2$. Nuclear modification factors for charm and bottom muons are presented as a function of muon transverse momentum in intervals of Pb+Pb collision centrality. The measured nuclear modification factors quantify a significant suppression of the yields of muons from decays of charm and bottom hadrons, with stronger effects for muons from charm hadron decays.
Summary of charm muon double differential cross section in pp collisions at 5.02 TeV as a function of pT. Uncertainties are statistical and systematic, respectively.
Summary of charm muon per-event invariant yields in Pb+Pb collisions at 5.02 TeV as a function of pT for five different centrality intervals. Uncertainties are statistical and systematic, respectively.
Summary of bottom muon per-event invariant yields in Pb+Pb collisions at 5.02 TeV as a function of pT for five different centrality intervals. Uncertainties are statistical and systematic, respectively.
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.
An exotic narrow state in the $D^0D^0\pi^+$ mass spectrum just below the $D^{*+}D^0$ mass threshold is studied using a data set corresponding to an integrated luminosity of 9 fb$^{-1}$ acquired with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The state is consistent with the ground isoscalar $T^+_{cc}$ tetraquark with a quark content of $cc\bar{u}\bar{d}$ and spin-parity quantum numbers $\mathrm{J}^{\mathrm{P}}=1^+$. Study of the $DD$ mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell $D^{*+}$ mesons is confirmed by the $D^0\pi^+$ mass distribution. The mass of the resonance and its coupling to the $D^{*}D$ system are analysed. Resonance parameters including the pole position, scattering length, effective range and compositeness are measured to reveal important information about the nature of the $T^+_{cc}$ state. In addition, an unexpected dependence of the production rate on track multiplicity is observed.
Distribution of $D^0 D^0 \pi^+$ mass where the contribution of the non-$D^0$ background has been statistically subtracted. Uncertainties on the data points are statistical only and represent one standard deviation, calculated as a sum in quadrature of the assigned weights from the background-subtraction procedure.
Mass distribution for $D^0 \pi^+$ pairs from selected $D^0 D^0 \pi^+$ candidates with a mass below the $D^{*+}D^0$ mass threshold with non-$D^0$ background subtracted. Uncertainties on the data points are statistical only and represent one standard deviation, calculated as a sum in quadrature of the assigned weights from the background-subtraction procedure.
$D^0 D^0$~mass distributions for selected candidates with the $D^0$ background subtracted. Uncertainties on the data points are statistical only and represent one standard deviation, calculated as a sum in quadrature of the assigned weights from the background-subtraction procedure.
Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. The observation of a new type of hadronic state, a doubly charmed tetraquark containing two charm quarks, an anti-$u$ and an anti-$d$ quark, is reported using data collected by the LHCb experiment at the Large Hadron Collider. This exotic state with a mass of about 3875 MeV$/c^2$ manifests itself as a narrow peak in the mass spectrum of $D^0D^0\pi^+$ mesons just below the $D^{*+}D^0$ mass threshold. The near threshold mass together with a strikingly narrow width reveals the resonance nature of the state.
Distribution of $D^0 D^0 \pi^+$ mass where the contribution of the non-$D^0$ background has been statistically subtracted. Uncertainties on the data points are statistical only and represent one standard deviation, calculated as a sum in quadrature of the assigned weights from the background-subtraction procedure.
Distribution of $D^0 D^0 \pi^+$ mass where the contribution of the non-$D^0$ background has been statistically subtracted by assigning the a weight to every candidate.
The B$^0_s$ and B$^+$ production yields are measured in PbPb collisions at a center-of-mass energy per nucleon pair of 5.02 TeV. The data sample, collected with the CMS detector at the LHC, corresponds to an integrated luminosity of 1.7 nb$^{-1}$. The mesons are reconstructed in the exclusive decay channels B$^0_s$$\to$ J/$\psi(\mu^+\mu^-)\phi($K$^+$K$^-)$ and B$^+$$\to$ J/$\psi(\mu^+\mu^-)$K$^+$, in the transverse momentum range 7-50 GeV/c and absolute rapidity 0-2.4. The B$^0_s$ meson is observed with a statistical significance in excess of five standard deviations for the first time in nucleus-nucleus collisions. The measurements are performed as functions of the transverse momentum of the B mesons and of the PbPb collision centrality. The ratio of production yields of B$^0_s$ and B$^+$ is measured and compared to theoretical models that include quark recombination effects.
The acceptance- and efficiency-corrected yields for the $\mathrm{B}^{0}_{\mathrm{s}}$ mesons, scaled by $T_{\mathrm{AA}}$ and $N_{\text{MB}}$ in PbPb collisions at $\sqrt{s_{NN}}=5.02$ TeV. The results are shown as a function of the meson $p_{T}$.
The acceptance- and efficiency-corrected yields for the $\mathrm{B}^{+}$ mesons, scaled by $T_{\mathrm{AA}}$ and $N_{\text{MB}}$ in PbPb collisions at $\sqrt{s_{NN}}=5.02$ TeV. The results are shown as a function of the meson $p_{T}$.
The acceptance- and efficiency-corrected yields for the $\mathrm{B}^{0}_{\mathrm{s}}$ mesons, scaled by $T_{\mathrm{AA}}$ and $N_{\text{MB}}$ in PbPb collisions at $\sqrt{s_{NN}}=5.02$ TeV. The results are shown as a function of the event $\langle N_{part} \rangle$.
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).
This article presents the results of two studies of Higgs boson properties using the $WW^*(\rightarrow e\nu\mu\nu)jj$ final state, based on a dataset corresponding to 36.1/fb of $\sqrt{s}$=13 TeV proton$-$proton collisions recorded by the ATLAS experiment at the Large Hadron Collider. The first study targets Higgs boson production via gluon$-$gluon fusion and constrains the CP properties of the effective Higgs$-$gluon interaction. Using angular distributions and the overall rate, a value of $\tan(\alpha) = 0.0 \pm 0.4$ stat. $ \pm 0.3$ syst is obtained for the tangent of the mixing angle for CP-even and CP-odd contributions. The second study exploits the vector-boson fusion production mechanism to probe the Higgs boson couplings to longitudinally and transversely polarised $W$ and $Z$ bosons in both the production and the decay of the Higgs boson; these couplings have not been directly constrained previously. The polarisation-dependent coupling-strength scale factors are defined as the ratios of the measured polarisation-dependent coupling strengths to those predicted by the Standard Model, and are determined using rate and kinematic information to be $a_L=0.91^{+0.10}_{-0.18}$(stat.)$^{+0.09}_{-0.17}$(syst.) and $a_{T}=1.2 \pm 0.4 $(stat.)$ ^{+0.2}_{-0.3} $(syst.). These coupling strengths are translated into pseudo-observables, resulting in $\kappa_{VV}= 0.91^{+0.10}_{-0.18}$(stat.)$^{+0.09}_{-0.17}$(syst.) and $\epsilon_{VV} =0.13^{+0.28}_{-0.20}$ (stat.)$^{+0.08}_{-0.10}$(syst.). All results are consistent with the Standard Model predictions.
Post-fit NFs and their uncertainties for the Z+jets, top and WW backgrounds. Both sets of normalisation factors differ slightly depending on which (B)SM model is tested, but are consistent within their total uncertainties.
Post-fit event yields in the signal and control regions obtained from the study of the signal strength parameter $\mu^{\text{ggF+2jets}}$. The quoted uncertainties include the theoretical and experimental systematic sources and those due to sample statistics. The fit constrains the total expected yield to the observed yield. The diboson background is split into $W W$ and non-$W W$ contributions.
Breakdown of the main contributions to the total uncertainty on $\tan \alpha$ based on the fit that exploits both shape and rate information. Individual sources of systematic uncertainty are grouped into either the theoretical or the experimental uncertainty. The sum in quadrature of the individual components differs from the total uncertainty due to correlations between the components.
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