Search for heavy long-lived charged $R$-hadrons with the ATLAS detector in 3.2 fb$^{-1}$ of proton--proton collision data at $\sqrt{s} = 13$ TeV

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Lett.B 760 (2016) 647-665, 2016.
Inspire Record 1470936 DOI 10.17182/hepdata.73717

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.

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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.

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Search for supersymmetry at $\sqrt{s}=13$ TeV in final states with jets and two same-sign leptons or three leptons with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Eur.Phys.J.C 76 (2016) 259, 2016.
Inspire Record 1424844 DOI 10.17182/hepdata.72792

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.

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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.

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Search for supersymmetry at sqrt(s)=8 TeV in final states with jets and two same-sign leptons or three leptons with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
JHEP 06 (2014) 035, 2014.
Inspire Record 1289225 DOI 10.17182/hepdata.63682

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 jets originating from b-quarks, missing transverse momentum and other observables to extend its sensitivity. The analysis uses a data sample corresponding to a total integrated luminosity of 20.3 fb$^{-1}$ of $\sqrt{s} =$ 8 TeV proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider in 2012. No deviation from the Standard Model expectation is observed. New or significantly improved exclusion limits are set on a wide variety of supersymmetric models in which the lightest squark can be of the first, second or third generations, and in which R-parity can be conserved or violated.

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Numbers of observed and background events for SR0b for each bin of the distribution in Meff. The table corresponds to Fig. 4(b). The statistical and systematic uncertainties are combined for the expected backgrounds.

Numbers of observed and background events for SR1b for each bin of the distribution in Meff. The table corresponds to Fig. 4(c). The statistical and systematic uncertainties are combined for the predicted numbers.

Numbers of observed and background events for SR3b for each bin of the distribution in Meff. The table corresponds to Fig. 4(a). The statistical and systematic uncertainties are combined for the predicted numbers.

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Measurement of the inclusive and differential WZ production cross sections, polarization angles, and triple gauge couplings in pp collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
JHEP 07 (2022) 032, 2022.
Inspire Record 1949191 DOI 10.17182/hepdata.114362

The associated production of a W and a Z boson is studied in final states with multiple leptons produced in proton-proton (pp) collisions at a centre-of-mass energy of 13 TeV using 137 fb$^{-1}$ of data collected with the CMS detector at the LHC. A measurement of the total inclusive production cross section yields $\sigma_{\text{tot}}$(pp $\to$ WZ) = 50.6 $\pm$ 0.8 (stat) $\pm$ 1.5 (syst) $\pm$ 1.1 (lumi) $\pm$ 0.5 (theo) pb. Measurements of the fiducial and differential cross sections for several key observables are also performed in all the final-state lepton flavour and charge compositions with a total of three charged leptons, which can be electrons or muons. All results are compared with theoretical predictions computed up to next-to-next-to-leading order in quantum chromodynamics plus next-to-leading order in electroweak theory and for various sets of parton distribution functions. The results include direct measurements of the charge asymmetry and the W and Z vector boson polarization. The first observation of longitudinally polarized W bosons in WZ production is reported. Anomalous gauge couplings are searched for, leading to new constraints on beyond-the-standard-model contributions to the WZ triple gauge coupling.

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Distribution of the three leading leptons flavour in the CR-ZZ with uncertainties evaluated after the inclusive cross section fit

Distribution of the jet multiplicity in the CR-ttZ with uncertainties evaluated after the inclusive cross section fit

Distribution of the three leading leptons flavour in the CR-conv with uncertainties evaluated after the inclusive cross section fit

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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.

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Lower mass requirement for signal regions.

Lower mass requirement for signal regions.

Lower mass requirement for signal regions.

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Constraining R-parity violating Minimal Supergravity with stau_1 LSP in a four lepton final state with missing transverse momentum

The ATLAS collaboration
ATLAS-CONF-2012-035, 2012.
Inspire Record 1204284 DOI 10.17182/hepdata.58712

This note describes an interpretation of a search for supersymmetry in final states with at least four isolated leptons (electrons or muons) and missing transverse momentum. The search used 2.06 fb$^{−1}$ of proton-proton collision data collected with the ATLAS experiment, and found no significant excess above expectations from Standard Model processes. Limits are shown for the Minimal Supergravity/Constrained Minimal Supersymmetric Standard Model (mSUGRA/CMSSM) with $m_0=A_0=0$, $\mu>0$ and one $R$-parity violating parameter $\lambda_{121}=0.032$ at the grand unification scale $m_{GUT}$. Keeping these parameters fixed, values of $m_{1/2}<800$ GeV are excluded at 95% CL if tan$\beta < 40$ and $m_{\tilde{\tau}_1}>80$ GeV. These are the first limits from the LHC experiments on a model with a $\tilde{\tau}_1$ as the lightest supersymmetric particle.

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Observed 95% CL exclusion limit in the m_{1/2}-Tan(Beta) plane.

Expected 95% CL exclusion limit in the m_{1/2}-Tan(Beta) plane.

Observed and Expected CLs values in the m_{1/2}-Tan(Beta) plane Note: lower bound is 0.0001.

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Search for supersymmetry in events with three leptons and missing transverse momentum in sqrt(s) = 7 TeV pp collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.Lett. 108 (2012) 261804, 2012.
Inspire Record 1112263 DOI 10.17182/hepdata.58756

A search for the weak production of charginos and neutralinos into final states with three electrons or muons and missing transverse momentum is presented. The analysis uses 2.06 fb^-1 of sqrt(s) = 7 TeV proton-proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with standard model expectations in two signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric and simplified models. For the simplified models, degenerate lightest chargino and next-to-lightest neutralino masses up to 300 GeV are excluded for mass differences from the lightest neutralino up to 300 GeV.

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Transverse momentum distribution for the first leading lepton for events in the SR1 signal region for DATA and SM predictions.

Transverse momentum distribution for the first leading lepton for events in the SR2 signal region for DATA and SM predictions.

Transverse momentum distribution for the second leading lepton for events in the SR1 signal region for DATA and SM predictions.

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Search for supersymmetry in events with four or more leptons in $\sqrt{s}$ = 8 TeV pp collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.D 90 (2014) 052001, 2014.
Inspire Record 1297226 DOI 10.17182/hepdata.63284

Results from a search for supersymmetry in events with four or more leptons including electrons, muons and taus are presented. The analysis uses a data sample corresponding to 20.3 $fb^{-1}$ of proton--proton collisions delivered by the Large Hadron Collider at $\sqrt{s}$ = 8 TeV and recorded by the ATLAS detector. Signal regions are designed to target supersymmetric scenarios that can be either enriched in or depleted of events involving the production of a $Z$ boson. No significant deviations are observed in data from Standard Model predictions and results are used to set upper limits on the event yields from processes beyond the Standard Model. Exclusion limits at the 95% confidence level on the masses of relevant supersymmetric particles are obtained. In R-parity-violating simplified models with decays of the lightest supersymmetric particle to electrons and muons, limits of 1350 GeV and 750 GeV are placed on gluino and chargino masses, respectively. In R-parity-conserving simplified models with heavy neutralinos decaying to a massless lightest supersymmetric particle, heavy neutralino masses up to 620 GeV are excluded. Limits are also placed on other supersymmetric scenarios.

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The ETmiss distribution in VR0Z.

The effective mass distribution in VR0Z.

The ETmiss distribution in VR2Z.

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Search for heavy long-lived multi-charged particles in $pp$ collisions at $\sqrt{s}$ = 8 TeV using the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Eur.Phys.J.C 75 (2015) 362, 2015.
Inspire Record 1360282 DOI 10.17182/hepdata.67348

A search for heavy long-lived multi-charged particles is performed using the ATLAS detector at the LHC. Data collected in 2012 at $\sqrt{s}$=8 TeV from $pp$ collisions corresponding to an integrated luminosity of $20.3$ fb$^{-1}$ are examined. Particles producing anomalously high ionisation, consistent with long-lived massive particles with electric charges from $|q|=2e$ to $|q|=6e$ are searched for. No signal candidate events are observed, and 95\% confidence level cross-section upper limits are interpreted as lower mass limits for a Drell--Yan production model. The mass limits range between 660 and 785 GeV.

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The observed event yield in data in the B region, the probability $f$ to find a particle above the respective $S$(MDT dE/dx) value before tight selection and the expected background yield in the signal region D with its statistical uncertainty. The last column shows the observed event yield in the D region.

Overview of separate contributions (in %) to the systematic uncertainty on the signal. The total uncertainty is given by the quadratic sum of the individual uncertainties.


Search for massive, long-lived particles using multitrack displaced vertices or displaced lepton pairs in pp collisions at $\sqrt{s}$ = 8 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.D 92 (2015) 072004, 2015.
Inspire Record 1362183 DOI 10.17182/hepdata.68777

Many extensions of the Standard Model posit the existence of heavy particles with long lifetimes. This article presents the results of a search for events containing at least one long-lived particle that decays at a significant distance from its production point into two leptons or into five or more charged particles. This analysis uses a data sample of proton-proton collisions at $\sqrt{s}$ = 8 TeV corresponding to an integrated luminosity of 20.3 fb$^{-1}$ collected in 2012 by the ATLAS detector operating at the Large Hadron Collider. No events are observed in any of the signal regions, and limits are set on model parameters within supersymmetric scenarios involving R-parity violation, split supersymmetry, and gauge mediation. In some of the search channels, the trigger and search strategy are based only on the decay products of individual long-lived particles, irrespective of the rest of the event. In these cases, the provided limits can easily be reinterpreted in different scenarios.

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Vertex-level efficiency as a function of the vertex radial position for an RPV SUSY model of squark production with $\tilde{q}\to q[\tilde{\chi}_1^0\to\mu qq]$, where $m(\tilde{q}) = 700$ GeV, $m(\tilde{\chi}_1^0) = 494$ GeV and $c\tau(\tilde{\chi}_1^0)$ = 175 mm. This result is also represented in Figure 3b and Auxiliary Figure 1.

Vertex-level efficiency as a function of the vertex radial position for an RPV SUSY model of squark production with $\tilde{q}\to q[\tilde{\chi}_1^0\to\mu qq]$, where $m(\tilde{q}) = 700$ GeV, $m(\tilde{\chi}_1^0) = 108$ GeV and $c\tau(\tilde{\chi}_1^0)$ = 101 mm.

Vertex-level efficiency as a function of the vertex radial position for an RPV SUSY model of squark production with $\tilde{q}\to q[\tilde{\chi}_1^0\to\mu qb]$, where $m(\tilde{q}) = 700$ GeV, $m(\tilde{\chi}_1^0) = 494$ GeV and $c\tau(\tilde{\chi}_1^0)$ = 175 mm. The other SUSY model point in the figure is tabulated in http://hepdata.cedar.ac.uk/view/ins1362183/d1.

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