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Search for a scalar or pseudoscalar dilepton resonance produced in association with a massive vector boson or top quark-antiquark pair in multilepton events at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
Phys.Rev.D 110 (2024) 012013, 2024.
Inspire Record 2759506 DOI 10.17182/hepdata.132367

A search for beyond the standard model spin-0 bosons, $\phi$, that decay into pairs of electrons, muons, or tau leptons is presented. The search targets the associated production of such bosons with a W or Z gauge boson, or a top quark-antiquark pair, and uses events with three or four charged leptons, including hadronically decaying tau leptons. The proton-proton collision data set used in the analysis was collected at the LHC from 2016 to 2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138 fb$^{-1}$. The observations are consistent with the predictions from standard model processes. Upper limits are placed on the product of cross sections and branching fractions of such new particles over the mass range of 15 to 350 GeV with scalar, pseudoscalar, or Higgs-boson-like couplings, as well as on the product of coupling parameters and branching fractions. Several model-dependent exclusion limits are also presented. For a Higgs-boson-like $\phi$ model, limits are set on the mixing angle of the Higgs boson with the $\phi$ boson. For the associated production of a $\phi$ boson with a top quark-antiquark pair, limits are set on the coupling to top quarks. Finally, limits are set for the first time on a fermiophilic dilaton-like model with scalar couplings and a fermiophilic axion-like model with pseudoscalar couplings.

140 data tables

Binned representation of the control and signal regions for the combined multilepton event selection and the combined 2016–2018 data set. The control region bins follow their definitions as given in Table 1 of the paper, and the signal region bins correspond to the channels as defined by the lepton flavor composition. The normalizations of the background samples in the control regions are described in Sections 5.1 and 5.2 of the paper. All three (four) lepton events are required to have $\mathrm{Q_{\ell}=1 (0)}$, and those satisfying any of the control region requirements are removed from the signal region bins. All subsequent selections given in Tables 2 and 3 of the paper are based on events given in the signal region bins. The lower panel shows the ratio of observed events to the total expected SM background prediction (Obs/Exp), and the gray band represents the statistical uncertainties in the background prediction.

The $M_{OSSF}$ spectrum for the combined 2L1T, 2L2T, 3L, 3L1T, and 4L event selection (excluding the $\mathrm{Z\gamma}$ control region) and the combined 2016-2018 data set. All three (four) lepton events are required to have $\mathrm{Q_{\ell}=1 (0)}$. The lower panel shows the ratio of observed events to the total expected SM background prediction (Obs/Exp), and the gray band represents the statistical uncertainties in the background prediction.

Dilepton mass spectra for the low mass $W\phi($ee$)$ SR1 event selections for the combined 2016–2018 data set. The lower panel shows the ratio of observed events to the total expected SM background prediction (Obs/Exp), and the gray band represents the sum of statistical and systematic uncertainties in the background prediction. The expected background distributions and the uncertainties are shown after the data is fit under the background-only hypothesis. For illustration, two example signal hypotheses for the production and decay of a scalar and a pseudoscalar $\phi$ boson are shown, and their masses (in units of GeV) are indicated in the legend. The signals are normalized to the product of the cross section and branching fraction of 10 fb.

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Search for supersymmetry in final states with a single electron or muon using angular correlations and heavy-object identification in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
JHEP 09 (2023) 149, 2023.
Inspire Record 2182749 DOI 10.17182/hepdata.135454

A search for supersymmetry is presented in events with a single charged lepton, electron or muon, and multiple hadronic jets. The data correspond to an integrated luminosity of 138 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of 13 TeV, recorded by the CMS experiment at the CERN LHC. The search targets gluino pair production, where the gluinos decay into final states with the lightest supersymmetric particle (LSP) and either a top quark-antiquark ($\mathrm{t\bar{t}}$) pair, or a light-flavor quark-antiquark ($\mathrm{q\bar{q}}$) pair and a virtual or on-shell W boson. The main backgrounds, $\mathrm{t\bar{t}}$ pair and W+jets production, are suppressed by requirements on the azimuthal angle between the momenta of the lepton and of its reconstructed parent W boson candidate, and by top quark and W boson identification based on a machine-learning technique. The number of observed events is consistent with the expectations from standard model processes. Limits are evaluated on supersymmetric particle masses in the context of two simplified models of gluino pair production. Exclusions for gluino masses reach up to 2120 (2050) GeV at 95% confidence level for a model with gluino decay to a $\mathrm{t\bar{t}}$ pair (a $\mathrm{q\bar{q}}$ pair and a W boson) and the LSP. For the same models, limits on the mass of the LSP reach up to 1250 (1070) GeV.

36 data tables

Signal and background distributions of the $\Delta \phi$ variable, as predicted by simulation, for the multi-b analysis, requiring $n_{\textrm{jet}}\geq6$, $L_T>250~\mathrm{GeV}$, $H_T>500~\mathrm{GeV}$. The predicted signal distributions are also shown for two representative combinations of (gluino, neutralino) masses with large (2.2, 0.1) $\mathrm{TeV}$ and small (1.8, 1.3) $\mathrm{TeV}$ mass differences.

Signal and background distributions of the $\Delta \phi$ variable, as predicted by simulation, for the zero-b analysis, requiring $n_{\textrm{jet}}\geq6$, $L_T>350~\mathrm{GeV}$, $H_T>750~\mathrm{GeV}$. The predicted signal distributions are also shown for two representative combinations of (gluino, neutralino) masses with large (2.2, 0.1) $\mathrm{TeV}$ and small (1.8, 1.3) $\mathrm{TeV}$ mass differences.

Distributions of $\Delta\phi$ as obtained from simulation, requiring various $\textrm{t}$ tag multiplicities for the total background.

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Search for exotic decays of the Higgs boson into long-lived particles in $pp$ collisions at $\sqrt{s} = 13$ TeV using displaced vertices in the ATLAS inner detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
JHEP 11 (2021) 229, 2021.
Inspire Record 1882568 DOI 10.17182/hepdata.106655

A novel search for exotic decays of the Higgs boson into pairs of long-lived neutral particles, each decaying into a bottom quark pair, is performed using 139 fb$^{-1}$ of $\sqrt{s} = 13$ TeV proton-proton collision data collected with the ATLAS detector at the LHC. Events consistent with the production of a Higgs boson in association with a leptonically decaying $Z$ boson are analysed. Long-lived particle (LLP) decays are reconstructed from inner-detector tracks as displaced vertices with high mass and track multiplicity relative to Standard Model processes. The analysis selection requires the presence of at least two displaced vertices, effectively suppressing Standard Model backgrounds. The residual background contribution is estimated using a data-driven technique. No excess over Standard Model predictions is observed, and upper limits are set on the branching ratio of the Higgs boson to LLPs. Branching ratios above 10% are excluded at 95% confidence level for LLP mean proper lifetimes $c\tau$ as small as 4 mm and as large as 100 mm. For LLP masses below 40 GeV, these results represent the most stringent constraint in this lifetime regime.

7 data tables

95% CL exclusion limits on $\mathcal{B}(H\rightarrow aa \rightarrow b\bar{b}b\bar{b})$ for $m_a = 16$ GeV.

95% CL exclusion limits on $\mathcal{B}(H\rightarrow aa \rightarrow b\bar{b}b\bar{b})$ for $m_a = 25$ GeV.

95% CL exclusion limits on $\mathcal{B}(H\rightarrow aa \rightarrow b\bar{b}b\bar{b})$ for $m_a = 35$ GeV.

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Search for dark matter produced in association with a single top quark in $\sqrt{s}=13$ TeV $pp$ collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
Eur.Phys.J.C 81 (2021) 860, 2021.
Inspire Record 1831036 DOI 10.17182/hepdata.99906

This paper presents a search for dark matter in the context of a two-Higgs-doublet model together with an additional pseudoscalar mediator, $a$, which decays into the dark-matter particles. Processes where the pseudoscalar mediator is produced in association with a single top quark in the 2HDM+$a$ model are explored for the first time at the LHC. Several final states which include either one or two charged leptons (electrons or muons) and a significant amount of missing transverse momentum are considered. The analysis is based on proton-proton collision data collected with the ATLAS experiment at $\sqrt{s} = 13$ TeV during LHC Run2 (2015-2018), corresponding to an integrated luminosity of 139 fb$^{-1}$. No significant excess above the Standard Model predictions is found. The results are expressed as 95% confidence-level limits on the parameters of the signal models considered.

71 data tables

Efficiencies of the DMt samples in the tW1L channel for all bins in the SR. The efficiency is defined as the number of weighted reconstructed events over the number of weighted TRUTH events in the SR. The maps include all samples in the $m_a - m_H$ plane with $tan\beta = 1$.

Acceptances on TRUTH level of the DMt samples in the tW1L channel for all bins in the SR. The acceptance is defined as the number of weighted TRUTH events in the SR over the number of expected events without any selections. The maps include all samples in the $m_a - m_H$ plane with $tan\beta = 1$.

Efficiencies of the DMt samples in the tW1L channel for all bins in the SR. The efficiency is defined as the number of weighted reconstructed events over the number of weighted TRUTH events in the SR. The maps include all samples in the $m_H - tan\beta$ plane with $m_a = 250~GeV$.

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