Constraints on spin-0 dark matter mediators and invisible Higgs decays using ATLAS 13 TeV $pp$ collision data with two top quarks and missing transverse momentum in the final state

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, D.C. ; et al.
Eur.Phys.J.C 83 (2023) 503, 2023.
Inspire Record 2180393 DOI 10.17182/hepdata.129623

This paper presents a statistical combination of searches targeting final states with two top quarks and invisible particles, characterised by the presence of zero, one or two leptons, at least one jet originating from a $b$-quark and missing transverse momentum. The analyses are searches for phenomena beyond the Standard Model consistent with the direct production of dark matter in $pp$ collisions at the LHC, using 139 fb$^{-\text{1}}$ of data collected with the ATLAS detector at a centre-of-mass energy of 13 TeV. The results are interpreted in terms of simplified dark matter models with a spin-0 scalar or pseudoscalar mediator particle. In addition, the results are interpreted in terms of upper limits on the Higgs boson invisible branching ratio, where the Higgs boson is produced according to the Standard Model in association with a pair of top quarks. For scalar (pseudoscalar) dark matter models, with all couplings set to unity, the statistical combination extends the mass range excluded by the best of the individual channels by 50 (25) GeV, excluding mediator masses up to 370 GeV. In addition, the statistical combination improves the expected coupling exclusion reach by 14% (24%), assuming a scalar (pseudoscalar) mediator mass of 10 GeV. An upper limit on the Higgs boson invisible branching ratio of 0.38 (0.30$^{+\text{0.13}}_{-\text{0.09}}$) is observed (expected) at 95% confidence level.

40 data tables

Post-fit signal region yields for the tt0L-high and the tt0L-low analyses. The bottom panel shows the statistical significance of the difference between the SM prediction and the observed data in each region. '$t\bar{t}$ (other)' represents $t\bar{t}$ events without extra jets or events with extra light-flavour jets. 'Other' includes contributions from $t\bar{t}W$, $tZ$ and $tWZ$ processes. The total uncertainty in the SM expectation is represented with hatched bands and the expected distributions for selected signal models are shown as dashed lines.

Representative fit distribution in the signal region for the tt1L analysis: each bin of such distribution corresponds to a single SR included in the fit. 'Other' includes contributions from $t\bar{t}W$, $tZ$, $tWZ$ and $t\bar{t}$ (semileptonic) processes. The total uncertainty in the SM expectation is represented with hatched bands and the expected distributions for selected signal models are shown as dashed lines.

Representative fit distribution in the same flavour leptons signal region for the tt2L analysis: each bin of such distribution, starting from the red arrow, corresponds to a single SR included in the fit. 'FNP' includes the contribution from fake/non-prompt lepton background arising from jets (mainly $\pi/K$, heavy-flavour hadron decays and photon conversion) misidentified as leptons, estimated in a purely data-driven way. 'Other' includes contributions from $t\bar{t}W$, $tZ$ and $tWZ$ processes. The total uncertainty in the SM expectation is represented with hatched bands and the expected distributions for selected signal models are shown as dashed lines.

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Version 2
Search for heavy charged long-lived particles in the ATLAS detector in 31.6 fb$^{-1}$ of proton-proton collision data at $\sqrt{s} = 13$ TeV

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Rev.D 99 (2019) 092007, 2019.
Inspire Record 1718558 DOI 10.17182/hepdata.86565

A search for heavy charged long-lived particles is performed using a data sample of 36.1 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} = 13$ TeV collected by the ATLAS experiment at the Large Hadron Collider. The search is based on observables related to ionization energy loss and time of flight, which are sensitive to the velocity of heavy charged particles traveling significantly slower than the speed of light. Multiple search strategies for a wide range of lifetimes, corresponding to path lengths of a few meters, are defined as model-independently as possible, by referencing several representative physics cases that yield long-lived particles within supersymmetric models, such as gluinos/squarks ($R$-hadrons), charginos and staus. No significant deviations from the expected Standard Model background are observed. Upper limits at 95% confidence level are provided on the production cross sections of long-lived $R$-hadrons as well as directly pair-produced staus and charginos. These results translate into lower limits on the masses of long-lived gluino, sbottom and stop $R$-hadrons, as well as staus and charginos of 2000 GeV, 1250 GeV, 1340 GeV, 430 GeV and 1090 GeV, respectively.

60 data tables

- - - - - - - - Overview of HEPData Record - - - - - - - - <br/><br/> <b>Lower mass requirement for signal regions.</b> <ul> <li><a href="86565?version=1&table=Table1">Gluinos and squarks</a></li> <li><a href="86565?version=1&table=Table2">Staus and charginos</a></li> </ul> <b>Discovery regions:</b> <ul> <li><a href="86565?version=1&table=Table3">Yields</a></li> <li><a href="86565?version=1&table=Table6">p0-values and limits</a></li> </ul> <b>Signal yield tables:</b> <ul> <li><a href="86565?version=1&table=Table4">MS-agnostic R-hadron search</a></li> <li><a href="86565?version=1&table=Table5">Full-detector R-hadron search</a></li> <li><a href="86565?version=1&table=Table7">MS-agnostic search for metastable gluino R-hadrons</a></li> <li><a href="86565?version=1&table=Table8">Full-detector direct-stau search</a></li> <li><a href="86565?version=1&table=Table9">Full-detector chargino search</a></li> </ul> <b>Limits:</b> <ul> <li><a href="86565?version=1&table=Table10">Gluino R-hadron search</a></li> <li><a href="86565?version=1&table=Table11">Sbottom R-hadron search</a></li> <li><a href="86565?version=1&table=Table12">Stop R-hadron search</a></li> <li><a href="86565?version=1&table=Table13">Stau search</a></li> <li><a href="86565?version=1&table=Table14">Chargino search</a></li> <li><a href="86565?version=1&table=Table15">Meta-stable gluino R-hadron search</a></li> <li><a href="86565?version=1&table=Table17">Meta-stable gluino R-hadron search</a></li> </ul> <b>Acceptance and efficiency:</b> <ul> <li><a href="86565?version=1&table=Table16">MS-agnostic R-hadron search</a></li> </ul> <b>Truth quantities:</b> <ul> <li><a href="86565?version=1&table=Table18">Flavor composition of 800 GeV stop R-hadrons simulated using the generic model</a></li> <li><a href="86565?version=1&table=Table19">Flavor composition of 800 GeV anti-stop R-hadrons simulated using the generic model</a></li> <li><a href="86565?version=1&table=Table20">Flavor composition of 800 GeV stop R-hadrons simulated using the Regge model</a></li> <li><a href="86565?version=1&table=Table21">Flavor composition of 800 GeV anti-stop R-hadrons simulated using the Regge model</a></li> </ul> <b>Reinterpretation material:</b> <ul> <li><a href="86565?version=1&table=Table22">ETmiss trigger efficiency as function of true ETmiss</a></li> <li><a href="86565?version=1&table=Table23">Single-muon trigger efficiency as function of |eta| and beta</a></li> <li><a href="86565?version=1&table=Table24">Candidate reconstruction efficiency for ID+Calo selection</a></li> <li><a href="86565?version=1&table=Table25">Candidate reconstruction efficiency for loose selection</a></li> <li><a href="86565?version=1&table=Table26">Efficiency for a loose candidate to be promoted to a tight candidate</a></li> <li><a href="86565?version=1&table=Table27">Resolution and average of reconstructed dE/dx mass for a given simulated mass for ID+calo candidates</a></li> <li><a href="86565?version=1&table=Table28">Resolution and average of reconstructed ToF mass for a given simulated mass for ID+calo candidates</a></li> <li><a href="86565?version=1&table=Table29">Resolution and average of reconstructed ToF mass for a given simulated mass for FullDet candidates</a></li> </ul> <p><b>Pseudo-code snippets</b> and <b>example SLHA setups</b> are available in the "Resources" linked on the left, and more detailed reinterpretation material is available at <a href="http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2016-32/hepdata_info.pdf">http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2016-32/hepdata_info.pdf</a>.</p>

- - - - - - - - Overview of HEPData Record - - - - - - - - <br/><br/> <b>Lower mass requirement for signal regions.</b> <ul> <li><a href="86565?version=1&table=Table1">Gluinos and squarks</a></li> <li><a href="86565?version=1&table=Table2">Staus and charginos</a></li> </ul> <b>Discovery regions:</b> <ul> <li><a href="86565?version=1&table=Table3">Yields</a></li> <li><a href="86565?version=1&table=Table6">p0-values and limits</a></li> </ul> <b>Signal yield tables:</b> <ul> <li><a href="86565?version=1&table=Table4">MS-agnostic R-hadron search</a></li> <li><a href="86565?version=1&table=Table5">Full-detector R-hadron search</a></li> <li><a href="86565?version=1&table=Table7">MS-agnostic search for metastable gluino R-hadrons</a></li> <li><a href="86565?version=1&table=Table8">Full-detector direct-stau search</a></li> <li><a href="86565?version=1&table=Table9">Full-detector chargino search</a></li> </ul> <b>Limits:</b> <ul> <li><a href="86565?version=1&table=Table10">Gluino R-hadron search</a></li> <li><a href="86565?version=1&table=Table11">Sbottom R-hadron search</a></li> <li><a href="86565?version=1&table=Table12">Stop R-hadron search</a></li> <li><a href="86565?version=1&table=Table13">Stau search</a></li> <li><a href="86565?version=1&table=Table14">Chargino search</a></li> <li><a href="86565?version=1&table=Table15">Meta-stable gluino R-hadron search</a></li> <li><a href="86565?version=1&table=Table17">Meta-stable gluino R-hadron search</a></li> </ul> <b>Acceptance and efficiency:</b> <ul> <li><a href="86565?version=1&table=Table16">MS-agnostic R-hadron search</a></li> </ul> <b>Truth quantities:</b> <ul> <li><a href="86565?version=1&table=Table18">Flavor composition of 800 GeV stop R-hadrons simulated using the generic model</a></li> <li><a href="86565?version=1&table=Table19">Flavor composition of 800 GeV anti-stop R-hadrons simulated using the generic model</a></li> <li><a href="86565?version=1&table=Table20">Flavor composition of 800 GeV stop R-hadrons simulated using the Regge model</a></li> <li><a href="86565?version=1&table=Table21">Flavor composition of 800 GeV anti-stop R-hadrons simulated using the Regge model</a></li> </ul> <b>Reinterpretation material:</b> <ul> <li><a href="86565?version=1&table=Table22">ETmiss trigger efficiency as function of true ETmiss</a></li> <li><a href="86565?version=1&table=Table23">Single-muon trigger efficiency as function of |eta| and beta</a></li> <li><a href="86565?version=1&table=Table24">Candidate reconstruction efficiency for ID+Calo selection</a></li> <li><a href="86565?version=1&table=Table25">Candidate reconstruction efficiency for loose selection</a></li> <li><a href="86565?version=1&table=Table26">Efficiency for a loose candidate to be promoted to a tight candidate</a></li> <li><a href="86565?version=1&table=Table27">Resolution and average of reconstructed dE/dx mass for a given simulated mass for ID+calo candidates</a></li> <li><a href="86565?version=1&table=Table28">Resolution and average of reconstructed ToF mass for a given simulated mass for ID+calo candidates</a></li> <li><a href="86565?version=1&table=Table29">Resolution and average of reconstructed ToF mass for a given simulated mass for FullDet candidates</a></li> </ul> <p><b>Pseudo-code snippets</b> and <b>example SLHA setups</b> are available in the "Resources" linked on the left, and more detailed reinterpretation material is available at <a href="http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2016-32/hepdata_info.pdf">http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2016-32/hepdata_info.pdf</a>.</p>

Lower mass requirement for signal regions.

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