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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.

24 data tables match query

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 top squarks in final states with one isolated lepton, jets, and missing transverse momentum in $\sqrt{s}=13$ TeV $pp$ collisions with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Rev.D 94 (2016) 052009, 2016.
Inspire Record 1469069 DOI 10.17182/hepdata.74125

The results of a search for the stop, the supersymmetric partner of the top quark, in final states with one isolated electron or muon, jets, and missing transverse momentum are reported. The search uses the 2015 LHC $pp$ collision data at a center-of-mass energy of $\sqrt{s}=13$ TeV recorded by the ATLAS detector and corresponding to an integrated luminosity of 3.2 fb${}^{-1}$. The analysis targets two types of signal models: gluino-mediated pair production of stops with a nearly mass-degenerate stop and neutralino; and direct pair production of stops, decaying to the top quark and the lightest neutralino. The experimental signature in both signal scenarios is similar to that of a top quark pair produced in association with large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits on gluino and stop masses are set at 95% confidence level. The results extend the LHC Run-1 exclusion limit on the gluino mass up to 1460 GeV in the gluino-mediated scenario in the high gluino and low stop mass region, and add an excluded stop mass region from 745 to 780 GeV for the direct stop model with a massless lightest neutralino. The results are also reinterpreted to set exclusion limits in a model of vector-like top quarks.

60 data tables match query

Comparison of data with estimated backgrounds in the $am_\text{T2}$ distribution with the STCR1 event selection except for the requirement on $am_\text{T2}$. The predicted backgrounds are scaled with normalization factors. The uncertainty band includes statistical and all experimental systematic uncertainties. The last bin includes overflow.

Comparison of data with estimated backgrounds in the $b$-tagged jet multiplicity with the STCR1 event selection except for the requirement on the $b$-tagged jet multiplicity. Furthermore, the $\Delta R(b_1,b_2)$ requirement is dropped. The predicted backgrounds are scaled with normalization factors. The uncertainty band includes statistical and all experimental systematic uncertainties. The last bin includes overflow.

Comparison of data with estimated backgrounds in the $\Delta R(b_1,b_2)$ distribution with the STCR1 event selection except for the requirement on $\Delta R(b_1,b_2)$. The predicted backgrounds are scaled with normalization factors. The uncertainty band includes statistical and all experimental systematic uncertainties. The last bin includes overflow.

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Search for squarks and gluinos in final states with jets and missing transverse momentum at $\sqrt{s}=$ 13 TeV with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Eur.Phys.J.C 76 (2016) 392, 2016.
Inspire Record 1458270 DOI 10.17182/hepdata.74253

A search for squarks and gluinos in final states containing hadronic jets, missing transverse momentum but no electrons or muons is presented. The data were recorded in 2015 by the ATLAS experiment in $\sqrt{s}=$ 13 TeV proton--proton collisions at the Large Hadron Collider. No excess above the Standard Model background expectation was observed in 3.2 fb$^{-1}$ of analyzed data. Results are interpreted within simplified models that assume R-parity is conserved and the neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1.51 TeV for a simplified model incorporating only a gluino octet and the lightest neutralino, assuming the lightest neutralino is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.03 TeV are excluded for a massless lightest neutralino. These limits substantially extend the region of supersymmetric parameter space excluded by previous measurements with the ATLAS detector.

105 data tables match query

Observed and expected background effective mass distributions in control region CRgamma for SR4jt.

Observed and expected background effective mass distributions in control region CRW for SR4jt.

Observed and expected background effective mass distributions in control region CRT for SR4jt.

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Search for photonic signatures of gauge-mediated supersymmetry in 8 TeV $pp$ collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.D 92 (2015) 072001, 2015.
Inspire Record 1383883 DOI 10.17182/hepdata.69300

A search is presented for photonic signatures motivated by generalised models of gauge-mediated supersymmetry breaking. This search makes use of $20.3{\rm fb}^{-1}$ of proton-proton collision data at $\sqrt{s}=8$ TeV recorded by the ATLAS detector at the LHC, and explores models dominated by both strong and electroweak production of supersymmetric partner states. Four experimental signatures incorporating an isolated photon and significant missing transverse momentum are explored. These signatures include events with an additional photon, lepton, $b$-quark jet, or jet activity not associated with any specific underlying quark flavor. No significant excess of events is observed above the Standard Model prediction and model-dependent 95% confidence-level exclusion limits are set.

32 data tables match query

Observed and expected exclusion limits in the gluino-bino mass plane, using the $\rm{SR}^{\gamma\gamma}_{S-H}$ analysis for $m_{\tilde{\chi}_1^0}\geq 800 {\rm GeV}$ and $\rm{SR}^{\gamma\gamma}_{S-L}$ analyses for $m_{\tilde{\chi}_1^0} < 800 {\rm GeV}$.

Observed and expected exclusion limits in the wino-bino mass plane, using the $\rm{SR}^{\gamma\gamma}_{W-H}$ analysis for $m_{\tilde{\chi}_1^0}\geq 350 {\rm GeV}$ and $\rm{SR}^{\gamma\gamma}_{W-L}$ analyses for $m_{\tilde{\chi}_1^0} < 350 {\rm GeV}$.

Observed exclusion limits in the gluino-neutralino mass plane, for the higgsino-bino GGM model with $\mu < 0$, using the merged $\rm{SR}^{\gamma b}_{L}$ and $\rm{SR}^{\gamma b}_{H}$ analyses.

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Summary of the searches for squarks and gluinos using $\sqrt{s}$ = 8 TeV pp collisions with the ATLAS experiment at the LHC

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
JHEP 10 (2015) 054, 2015.
Inspire Record 1383884 DOI 10.17182/hepdata.69241

A summary is presented of ATLAS searches for gluinos and first- and second-generation squarks in final states containing jets and missing transverse momentum, with or without leptons or b-jets, in the $\sqrt{s}$ = 8 TeV data set collected at the Large Hadron Collider in 2012. This paper reports the results of new interpretations and statistical combinations of previously published analyses, as well as a new analysis. Since no significant excess of events over the Standard Model expectation is observed, the data are used to set limits in a variety of models. In all the considered simplified models that assume R-parity conservation, the limit on the gluino mass exceeds 1150 GeV at 95% confidence level, for an LSP mass smaller than 100 GeV. Furthermore, exclusion limits are set for left-handed squarks in a phenomenological MSSM model, a minimal Supergravity/Constrained MSSM model, R-parity-violation scenarios, a minimal gauge-mediated supersymmetry breaking model, a natural gauge mediation model, a non-universal Higgs mass model with gaugino mediation and a minimal model of universal extra dimensions.

30 data tables match query

Acceptance for the loose channel of the Razor analysis for the direct squark-squark model.

Acceptance times efficiency for the loose channel of the Razor analysis for the direct squark-squark model.

Acceptance for the tight channel of the Razor analysis for the direct squark-squark model.

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Search for metastable heavy charged particles with large ionisation energy loss in $pp$ collisions at $\sqrt{s}$ = 8 TeV using the ATLAS experiment

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Eur.Phys.J.C 75 (2015) 407, 2015.
Inspire Record 1376482 DOI 10.17182/hepdata.68640

Many extensions of the Standard Model predict the existence of charged heavy long-lived particles, such as $R$-hadrons or charginos. These particles, if produced at the Large Hadron Collider, should be moving non-relativistically and are therefore identifiable through the measurement of an anomalously large specific energy loss in the ATLAS pixel detector. Measuring heavy long-lived particles through their track parameters in the vicinity of the interaction vertex provides sensitivity to metastable particles with lifetimes from 0.6 ns to 30 ns. A search for such particles with the ATLAS detector at the Large Hadron Collider is presented, based on a data sample corresponding to an integrated luminosity of 18.4 fb$^{-1}$ of $pp$ collisions at $\sqrt{s}$ = 8 TeV. No significant deviation from the Standard Model background expectation is observed, and lifetime-dependent upper limits on $R$-hadrons and chargino production are set. Gluino $R$-hadrons with 10 ns lifetime and masses up to 1185 GeV are excluded at 95$\%$ confidence level, and so are charginos with 15 ns lifetime and masses up to 482 GeV.

80 data tables match query

Ratio of the reconstructed mass, computed as the most probable value of a fit to a Landau distribution convolved with a Gaussian, to the generated mass, as a function of the generated mass for stable gluino R-hadrons, along with the half-width at half maximum of the reconstructed mass distribution normalised to the generated mass.

Efficiency for the calorimetric MET>80 GeV trigger as a function of the stable R-hadron mass.

Efficiency for the calorimetric MET>80 GeV trigger as a function of the metastable R-hadron mass. The R-hadron decays to g/qq plus neutralino of mass 100 GeV with a lifetime of 1 ns.

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Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at $\sqrt{s}=8$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
JHEP 04 (2015) 116, 2015.
Inspire Record 1339376 DOI 10.17182/hepdata.66986

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider (LHC) are reported. The search is based on proton-proton collision data at a centre-of-mass energy $\sqrt{s} = 8$ TeV collected in 2012, corresponding to an integrated luminosity of 20 fb$^{-1}$. No significant excess above the Standard Model expectation is observed. Limits are set on the parameters of a minimal universal extra dimensions model, excluding a compactification radius of $1/R_c=950$ GeV for a cut-off scale times radius ($\Lambda R_c$) of approximately 30, as well as on sparticle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV.

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Observed and expected $E_T^{miss}/m_{eff}$ distribution in soft single-lepton 3-jet signal region. The last bin includes the overflow.

Observed and expected $E_T^{miss}/m_{eff}$ distribution in soft single-lepton 5-jet signal region. The last bin includes the overflow.

Observed and expected $E_T^{miss}/m_{eff}$ distribution in soft single-lepton 3-jet inclusive signal region. The last bin includes the overflow.

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Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using $\sqrt{s}=8$ TeV proton--proton collision data

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
JHEP 09 (2014) 176, 2014.
Inspire Record 1298722 DOI 10.17182/hepdata.64973

A search for squarks and gluinos in final states containing high-$p_{\rm T}$ jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in $\sqrt{s}=8$ TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of $20.3 \mathrm{fb}^{-1}$. No significant excess above the Standard Model expectation is observed. Results are interpreted in a variety of simplified and specific supersymmetry-breaking models assuming that R-parity is conserved and that the lightest neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1330 GeV for a simplified model incorporating only a gluino and the lightest neutralino. For a simplified model involving the strong production of first- and second-generation squarks, squark masses below 850 GeV (440 GeV) are excluded for a massless lightest neutralino, assuming mass degenerate (single light-flavour) squarks. In mSUGRA/CMSSM models with $\tan\beta=30$, $A_0=-2m_0$ and $\mu> 0$, squarks and gluinos of equal mass are excluded for masses below 1700 GeV. Additional limits are set for non-universal Higgs mass models with gaugino mediation and for simplified models involving the pair production of gluinos, each decaying to a top squark and a top quark, with the top squark decaying to a charm quark and a neutralino. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector.

195 data tables match query

The effective mass distribution in 2-jet loose signal region.

The effective mass distribution in 2-jet medium and tight signal regions.

The effective mass distribution in 2-jet (W) signal region.

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Search for supersymmetry in events containing a same-flavour opposite-sign dilepton pair, jets, and large missing transverse momentum in $\sqrt{s}=8$ TeV $pp$ collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Eur.Phys.J.C 75 (2015) 318, 2015.
Inspire Record 1351762 DOI 10.17182/hepdata.67921

Two searches for supersymmetric particles in final states containing a same-flavour opposite-sign lepton pair, jets and large missing transverse momentum are presented. The proton-proton collision data used in these searches were collected at a centre-of-mass energy $\sqrt{s}=8$ TeV by the ATLAS detector at the Large Hadron Collider and corresponds to an integrated luminosity of 20.3 fb$^{-1}$. Two leptonic production mechanisms are considered: decays of squarks and gluinos with $Z$ bosons in the final state, resulting in a peak in the dilepton invariant mass distribution around the $Z$-boson mass; and decays of neutralinos (e.g. $\tilde{\chi}^{0}_{2} \rightarrow \ell^{+}\ell^{-}\tilde{\chi}^{0}_{1}$), resulting in a kinematic endpoint in the dilepton invariant mass distribution. For the former, an excess of events above the expected Standard Model background is observed, with a significance of 3 standard deviations. In the latter case, the data are well-described by the expected Standard Model background. The results from each channel are interpreted in the context of several supersymmetric models involving the production of squarks and gluinos.

60 data tables match query

The observed and expected dielectron invariant mass distribution in SR-Z. The negigible estimated contribution from Z+jets is omitted in these distributions.

The observed and expected dimuon invariant mass distribution in SR-Z. The negigible estimated contribution from Z+jets is omitted in these distributions.

The observed and expected $E_T^{miss}$ distribution in the dielectron SR-Z. The negigible estimated contribution from Z+jets is omitted in these distributions. The last bin contains the overflow.