A search for the direct production of the supersymmetric partners of $\tau$-leptons (staus) in final states with two hadronically decaying $\tau$-leptons is presented. The analysis uses a dataset of $pp$ collisions corresponding to an integrated luminosity of $139$ fb$^{-1}$, recorded with the ATLAS detector at the Large Hadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected Standard Model background is observed. Limits are derived in scenarios of direct production of stau pairs with each stau decaying into the stable lightest neutralino and one $\tau$-lepton in simplified models where the two stau mass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidence level for a massless lightest neutralino.
The observed upper limits on the model cross-section in units of pb for simplified models with combined ${\tilde{\tau}}^{+}_{R,L} {\tilde{\tau}}^{-}_{R,L}$ production. Three points at ${M({\tilde{\chi}}^{0}_{1})}=200GeV$ were removed from the plot but kept in the table because they overlapped with the plot's legend and are far from the exclusion contour.
The observed upper limits on the model cross-section in units of pb for simplified models with ${\tilde{\tau}}_L {\tilde{\tau}}_L$ only production. Three points at $M({\tilde{\chi}}^{0}_{1})=200GeV$ were removed from the plot but kept in the table because they overlapped with the plot's legend and are far from the exclusion contour.
The observed 95\% CL exclusion contours for the combined fit of SR-lowMass and SR-highMass for simplified models with combined ${\tilde{\tau}}^{+}_{R,L} {\tilde{\tau}}^{-}_{R,L}$ production.
A search for the electroweak production of charginos and sleptons decaying into final states with two electrons or muons is presented. The analysis is based on 139 fb$^{-1}$ of proton-proton collisions recorded by the ATLAS detector at the Large Hadron Collider at $\sqrt{s}=13$ TeV. Three $R$-parity-conserving scenarios where the lightest neutralino is the lightest supersymmetric particle are considered: the production of chargino pairs with decays via either $W$ bosons or sleptons, and the direct production of slepton pairs. The analysis is optimised for the first of these scenarios, but the results are also interpreted in the others. No significant deviations from the Standard Model expectations are observed and limits at 95 % confidence level are set on the masses of relevant supersymmetric particles in each of the scenarios. For a massless lightest neutralino, masses up to 420 GeV are excluded for the production of the lightest-chargino pairs assuming $W$-boson-mediated decays and up to 1 TeV for slepton-mediated decays, whereas for slepton-pair production masses up to 700 GeV are excluded assuming three generations of mass-degenerate sleptons.
- - - - - - - - Overview of HEPData Record - - - - - - - - <br/><br/> <b>Background Fit results:</b> <ul> <li><a href="89413?version=4&table=Background fit 1">CRs</a> <li><a href="89413?version=4&table=Background fit 2">VRs</a> <li><a href="89413?version=4&table=Background fit 5">inclusive DF-0J SRs</a> <li><a href="89413?version=4&table=Background fit 6">inclusive DF-1J SRs</a> <li><a href="89413?version=4&table=Background fit 3">inclusive SF-0J SRs</a> <li><a href="89413?version=4&table=Background fit 4">inclusive SF-1J SRs</a> </ul> <b>Kinematic distributions in VRs:</b> <ul> <li><a href="89413?version=4&table=VR kinematics 1">$m_{T2}$ in VR-top-low</a> <li><a href="89413?version=4&table=VR kinematics 2">$m_{T2}$ in VR-top-high</a> <li><a href="89413?version=4&table=VR kinematics 3">$E_T^{miss}$ in VR-WW-0J</a> <li><a href="89413?version=4&table=VR kinematics 4">$E_T^{miss}$ in VR-WW-1J</a> <li><a href="89413?version=4&table=VR kinematics 5">$E_T^{miss}$ sig in VR-VZ</a> <li><a href="89413?version=4&table=VR kinematics 6">$E_T^{miss}$ sig in VR-top-WW</a> </ul> <b>Kinematic distributions in SRs:</b> <ul> <li><a href="89413?version=4&table=SR kinematics 1">$m_{T2}$ in SR-SF-0J</a> <li><a href="89413?version=4&table=SR kinematics 2">$m_{T2}$ in SR-SF-1J</a> <li><a href="89413?version=4&table=SR kinematics 3">$m_{T2}$ in SR-DF-0J</a> <li><a href="89413?version=4&table=SR kinematics 4">$m_{T2}$ in SR-DF-1J</a> </ul> <b>Systematic uncertaities:</b> <ul> <li><a href="89413?version=4&table=Systematic uncertainties">dominant systematic uncertainties in the inclusive SRs</a> </ul> <b>Exclusion contours:</b> <ul> <li><a href="89413?version=4&table=Exclusion contour (exp) 1">expected exclusion contour direct chargino-pair production via W decay grid</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 1">observed exclusion contour direct chargino-pair production via W decay grid</a> <li><a href="89413?version=4&table=Exclusion contour (exp) 2">expected exclusion contour direct chargino-pair production via slepton decay grid</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 2">observed exclusion contour direct chargino-pair production via slepton decay grid</a> <li><a href="89413?version=4&table=Exclusion contour (exp) 3">expected exclusion contour direct slepton-pair production grid</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 3">observed exclusion contour direct slepton-pair production grid</a> </ul> <br/><br/><b>AUXILIARY MATERIAL</b><br/> <b>Background Fit in binned SRs:</b> <ul> <li><a href="89413?version=4&table=Background fit 7">binned DF-0J SRs</a> <li><a href="89413?version=4&table=Background fit 8">binned DF-1J SRs</a> <li><a href="89413?version=4&table=Background fit 9">binned SF-0J SRs</a> <li><a href="89413?version=4&table=Background fit 10">binned SF-1J SRs</a> </ul> <b>Exclusion contours:</b> <ul> <li><a href="89413?version=4&table=Exclusion contour (exp) 4">expected exclusion contour left-handed slepton-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 4">observed exclusion contour left-handed slepton-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (exp) 5">expected exclusion contour right-handed slepton-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 5">observed exclusion contour right-handed slepton-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (exp) 6">expected exclusion contour selectron-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 6">observed exclusion contour selectron-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (exp) 7">expected exclusion contour left-handed selectron-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 7">observed exclusion contour left-handed selectron-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (exp) 8">expected exclusion contour right-handed selectron-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 8">observed exclusion contour right-handed selectron-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (exp) 9">expected exclusion contour smuon-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 9">observed exclusion contour smuon-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (exp) 10">expected exclusion contour left-handed smuon-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 10">observed exclusion contour left-handed smuon-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (exp) 11">expected exclusion contour right-handed smuon-pair production</a> <li><a href="89413?version=4&table=Exclusion contour (obs) 11">observed exclusion contour right-handed smuon-pair production</a> </ul> <b>Cross section upper limits:</b> <ul> <li><a href="89413?version=4&table=xsec upper limits 1">upper limits on signal cross section for direct chargino-pair production via W decay</a> <li><a href="89413?version=4&table=xsec upper limits 2">upper limits on signal cross section for direct chargino-pair production via slepton decay</a> <li><a href="89413?version=4&table=xsec upper limits 3">upper limits on signal cross section for direct slepton-pair production</a> </ul> <b>Acceptances and Efficiencies for direct chargino-pair production via W decay grid </b> <ul> <li> <b>Acceptance</b> <br/> <a href="89413?version=4&table=Acceptance SR-DF-0J-[100,inf) for C1C1WW grid">SR-DF-0J-[100,inf) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[160,inf) for C1C1WW grid">SR-DF-0J-[160,inf) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[100,120) for C1C1WW grid">SR-DF-0J-[100,120) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[120,160) for C1C1WW grid">SR-DF-0J-[120,160) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[100,105) for C1C1WW grid">SR-DF-0J-[100,105) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[105,110) for C1C1WW grid">SR-DF-0J-[105,110) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[110,120) for C1C1WW grid">SR-DF-0J-[110,120) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[120,140) for C1C1WW grid">SR-DF-0J-[120,140) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[140,160) for C1C1WW grid">SR-DF-0J-[140,160) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[160,180) for C1C1WW grid">SR-DF-0J-[160,180) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[180,220) for C1C1WW grid">SR-DF-0J-[180,220) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[220,260) for C1C1WW grid">SR-DF-0J-[220,260) </a> <a href="89413?version=4&table=Acceptance SR-DF-0J-[260,inf) for C1C1WW grid">SR-DF-0J-[260,inf) </a><br/> <a href="89413?version=4&table=Acceptance SR-DF-1J-[100,inf) for C1C1WW grid">SR-DF-1J-[100,inf) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[160,inf) for C1C1WW grid">SR-DF-1J-[160,inf) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[100,120) for C1C1WW grid">SR-DF-1J-[100,120) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[120,160) for C1C1WW grid">SR-DF-1J-[120,160) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[100,105) for C1C1WW grid">SR-DF-1J-[100,105) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[105,110) for C1C1WW grid">SR-DF-1J-[105,110) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[110,120) for C1C1WW grid">SR-DF-1J-[110,120) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[120,140) for C1C1WW grid">SR-DF-1J-[120,140) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[140,160) for C1C1WW grid">SR-DF-1J-[140,160) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[160,180) for C1C1WW grid">SR-DF-1J-[160,180) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[180,220) for C1C1WW grid">SR-DF-1J-[180,220) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[220,260) for C1C1WW grid">SR-DF-1J-[220,260) </a> <a href="89413?version=4&table=Acceptance SR-DF-1J-[260,inf) for C1C1WW grid">SR-DF-1J-[260,inf) </a><br/> <a href="89413?version=4&table=Acceptance SR-SF-0J-[100,inf) for C1C1WW grid">SR-SF-0J-[100,inf) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[160,inf) for C1C1WW grid">SR-SF-0J-[160,inf) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[100,120) for C1C1WW grid">SR-SF-0J-[100,120) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[120,160) for C1C1WW grid">SR-SF-0J-[120,160) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[100,105) for C1C1WW grid">SR-SF-0J-[100,105) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[105,110) for C1C1WW grid">SR-SF-0J-[105,110) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[110,120) for C1C1WW grid">SR-SF-0J-[110,120) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[120,140) for C1C1WW grid">SR-SF-0J-[120,140) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[140,160) for C1C1WW grid">SR-SF-0J-[140,160) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[160,180) for C1C1WW grid">SR-SF-0J-[160,180) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[180,220) for C1C1WW grid">SR-SF-0J-[180,220) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[220,260) for C1C1WW grid">SR-SF-0J-[220,260) </a> <a href="89413?version=4&table=Acceptance SR-SF-0J-[260,inf) for C1C1WW grid">SR-SF-0J-[260,inf) </a><br/> <a href="89413?version=4&table=Acceptance SR-SF-1J-[100,inf) for C1C1WW grid">SR-SF-1J-[100,inf) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[160,inf) for C1C1WW grid">SR-SF-1J-[160,inf) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[100,120) for C1C1WW grid">SR-SF-1J-[100,120) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[120,160) for C1C1WW grid">SR-SF-1J-[120,160) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[100,105) for C1C1WW grid">SR-SF-1J-[100,105) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[105,110) for C1C1WW grid">SR-SF-1J-[105,110) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[110,120) for C1C1WW grid">SR-SF-1J-[110,120) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[120,140) for C1C1WW grid">SR-SF-1J-[120,140) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[140,160) for C1C1WW grid">SR-SF-1J-[140,160) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[160,180) for C1C1WW grid">SR-SF-1J-[160,180) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[180,220) for C1C1WW grid">SR-SF-1J-[180,220) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[220,260) for C1C1WW grid">SR-SF-1J-[220,260) </a> <a href="89413?version=4&table=Acceptance SR-SF-1J-[260,inf) for C1C1WW grid">SR-SF-1J-[260,inf) </a><br/> <li> <b>Efficiency</b> <br/> <a href="89413?version=4&table=Efficiency SR-DF-0J-[100,inf) for C1C1WW grid">SR-DF-0J-[100,inf) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[160,inf) for C1C1WW grid">SR-DF-0J-[160,inf) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[100,120) for C1C1WW grid">SR-DF-0J-[100,120) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[120,160) for C1C1WW grid">SR-DF-0J-[120,160) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[100,105) for C1C1WW grid">SR-DF-0J-[100,105) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[105,110) for C1C1WW grid">SR-DF-0J-[105,110) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[110,120) for C1C1WW grid">SR-DF-0J-[110,120) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[120,140) for C1C1WW grid">SR-DF-0J-[120,140) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[140,160) for C1C1WW grid">SR-DF-0J-[140,160) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[160,180) for C1C1WW grid">SR-DF-0J-[160,180) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[180,220) for C1C1WW grid">SR-DF-0J-[180,220) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[220,260) for C1C1WW grid">SR-DF-0J-[220,260) </a> <a href="89413?version=4&table=Efficiency SR-DF-0J-[260,inf) for C1C1WW grid">SR-DF-0J-[260,inf) </a><br/> <a href="89413?version=4&table=Efficiency SR-DF-1J-[100,inf) for C1C1WW grid">SR-DF-1J-[100,inf) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[160,inf) for C1C1WW grid">SR-DF-1J-[160,inf) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[100,120) for C1C1WW grid">SR-DF-1J-[100,120) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[120,160) for C1C1WW grid">SR-DF-1J-[120,160) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[100,105) for C1C1WW grid">SR-DF-1J-[100,105) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[105,110) for C1C1WW grid">SR-DF-1J-[105,110) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[110,120) for C1C1WW grid">SR-DF-1J-[110,120) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[120,140) for C1C1WW grid">SR-DF-1J-[120,140) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[140,160) for C1C1WW grid">SR-DF-1J-[140,160) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[160,180) for C1C1WW grid">SR-DF-1J-[160,180) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[180,220) for C1C1WW grid">SR-DF-1J-[180,220) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[220,260) for C1C1WW grid">SR-DF-1J-[220,260) </a> <a href="89413?version=4&table=Efficiency SR-DF-1J-[260,inf) for C1C1WW grid">SR-DF-1J-[260,inf) </a><br/> <a href="89413?version=4&table=Efficiency SR-SF-0J-[100,inf) for C1C1WW grid">SR-SF-0J-[100,inf) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[160,inf) for C1C1WW grid">SR-SF-0J-[160,inf) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[100,120) for C1C1WW grid">SR-SF-0J-[100,120) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[120,160) for C1C1WW grid">SR-SF-0J-[120,160) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[100,105) for C1C1WW grid">SR-SF-0J-[100,105) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[105,110) for C1C1WW grid">SR-SF-0J-[105,110) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[110,120) for C1C1WW grid">SR-SF-0J-[110,120) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[120,140) for C1C1WW grid">SR-SF-0J-[120,140) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[140,160) for C1C1WW grid">SR-SF-0J-[140,160) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[160,180) for C1C1WW grid">SR-SF-0J-[160,180) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[180,220) for C1C1WW grid">SR-SF-0J-[180,220) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[220,260) for C1C1WW grid">SR-SF-0J-[220,260) </a> <a href="89413?version=4&table=Efficiency SR-SF-0J-[260,inf) for C1C1WW grid">SR-SF-0J-[260,inf) </a><br/> <a href="89413?version=4&table=Efficiency SR-SF-1J-[100,inf) for C1C1WW grid">SR-SF-1J-[100,inf) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[160,inf) for C1C1WW grid">SR-SF-1J-[160,inf) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[100,120) for C1C1WW grid">SR-SF-1J-[100,120) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[120,160) for C1C1WW grid">SR-SF-1J-[120,160) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[100,105) for C1C1WW grid">SR-SF-1J-[100,105) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[105,110) for C1C1WW grid">SR-SF-1J-[105,110) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[110,120) for C1C1WW grid">SR-SF-1J-[110,120) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[120,140) for C1C1WW grid">SR-SF-1J-[120,140) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[140,160) for C1C1WW grid">SR-SF-1J-[140,160) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[160,180) for C1C1WW grid">SR-SF-1J-[160,180) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[180,220) for C1C1WW grid">SR-SF-1J-[180,220) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[220,260) for C1C1WW grid">SR-SF-1J-[220,260) </a> <a href="89413?version=4&table=Efficiency SR-SF-1J-[260,inf) for C1C1WW grid">SR-SF-1J-[260,inf) </a><br/> </ul> <b>Cutflow:</b> <ul> <li><a href="89413?version=4&table=Cutflow 1">Cutflow for direct chargino-pair production via W decay $m(\tilde{\chi}^{\pm}_1,\tilde{\chi}^{0}_1)=(300,50) GeV$</a> <li><a href="89413?version=4&table=Cutflow 2">Cutflow for direct chargino-pair production via slepton decay $m(\tilde{\chi}^{\pm}_1,\tilde{l},\tilde{\chi}^{0}_1)=(600,300,1) GeV$</a> <li><a href="89413?version=4&table=Cutflow 3">Cutflow for direct slepton-pair production $m(\tilde{l},\tilde{\chi}^{0}_1)=(400,200) GeV$</a> </ul> <b>SimpleAnalysis framework implementation</b> of the search SRs is available under "Resources" (purple button on the left)
Observed events and predicted background yields from the fit for the CRs. For backgrounds whose normalisation is extracted from the fit, the yield expected from the simulation before the fit is also reported. The background denoted as "Other" in the Table includes the non-dominant background sources for this analysis, i.e. Z+jets, $t\bar t$ +V, Higgs and Drell-Yan events. A "–" symbol indicates that the background contribution is negligible.
Observed events and predicted post-fit background yields in the VRs. For backgrounds whose normalisation is extracted from the fit in the CRs, the yield expected from the simulation before the fit is also reported. The background denoted as "Other" includes the non-dominant background sources for this analysis, i.e. Z+jets, $t\bar t$ +V, Higgs and Drell-Yan events. A "–" symbol indicates that the background contribution is negligible.
A search for long-lived particles decaying into an oppositely charged lepton pair, $\mu\mu$, $ee$, or $e\mu$, is presented using 32.8 fb$^{-1}$ of $pp$ collision data collected at $\sqrt{s}=13$ TeV by the ATLAS detector at the LHC. Candidate leptons are required to form a vertex, within the inner tracking volume of ATLAS, displaced from the primary $pp$ interaction region. No lepton pairs with an invariant mass greater than 12 GeV are observed, consistent with the background expectations derived from data. The detection efficiencies for generic resonances with lifetimes ($c\tau$) of 100-1000 mm decaying into a dilepton pair with masses between 0.1-1.0 TeV are presented as a function of $p_T$ and decay radius of the resonances to allow the extraction of upper limits on the cross sections for theoretical models. The result is also interpreted in a supersymmetric model in which the lightest neutralino, produced via squark-antisquark production, decays into $\ell^{+}\ell^{'-}\nu$ ($\ell, \ell^{'} = e$, $\mu$) with a finite lifetime due to the presence of R-parity violating couplings. Cross-section limits are presented for specific squark and neutralino masses. For a 700 GeV squark, neutralinos with masses of 50-500 GeV and mean proper lifetimes corresponding to $c\tau$ values between 1 mm to 6 m are excluded. For a 1.6 TeV squark, $c\tau$ values between 3 mm to 1 m are excluded for 1.3 TeV neutralinos.
<h1>Overview of reinterpretation material</h1><p><b>Important note:</b> A detailed explanation of the reinterpretation material can be found <a href="https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2017-04/hepdata_info.pdf">here</a>.<br/>Please read this stand-alone document before reinterpreting the search.</p><h2>Parameterized detection efficiencies</h2><p>RPV SUSY model: Tables <a href="90606?version=1&table=Table27">27</a> to <a href="90606?version=1&table=Table44">44</a><br/>Z' toy model: Tables <a href="90606?version=1&table=Table45">45</a> to <a href="90606?version=1&table=Table59">59</a></p><h2>Further material for the RPV SUSY model</h2><p>Acceptances: Tables <a href="90606?version=1&table=Table18">18</a> (ee), <a href="90606?version=1&table=Table19">19</a> (emu) and <a href="90606?version=1&table=Table20">20</a> (mumu)<br/>Detection efficiencies: Tables <a href="90606?version=1&table=Table21">21</a> (ee), <a href="90606?version=1&table=Table22">22</a> (emu) and <a href="90606?version=1&table=Table23">23</a> (mumu)<br/>Overall signal efficiencies: Tables <a href="90606?version=1&table=Table24">24</a> (ee), <a href="90606?version=1&table=Table25">25</a> (emu) and <a href="90606?version=1&table=Table26">26</a> (mumu)</p><h2>Further material for the Z' toy model</h2><p>Acceptances, detection efficiencies and overall signal efficiencies: Tables <a href="90606?version=1&table=Table60">60</a> (mZ' = 100 GeV) to <a href="90606?version=1&table=Table64">64</a> (mZ' = 1000 GeV)</p>
dRcos distribution of dimuon pairs (scaled) and dimuon vertices in the cosmic rays control region. The distribution of all dimuon pairs is scaled to the DV distribution.
Dependence of the overall signal efficiency on the transverse decay radius Rxy of the long-lived Z' for Z' -> ee. The error bars indicate the total uncertainties.
A search for a heavy charged-boson resonance decaying into a charged lepton (electron or muon) and a neutrino is reported. A data sample of 139 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} = 13$ TeV collected with the ATLAS detector at the LHC during 2015-2018 is used in the search. The observed transverse mass distribution computed from the lepton and missing transverse momenta is consistent with the distribution expected from the Standard Model, and upper limits on the cross section for $pp \to W^\prime \to \ell\nu$ are extracted ($\ell = e$ or $\mu$). These vary between 1.3 pb and 0.05 fb depending on the resonance mass in the range between 0.15 and 7.0 TeV at 95% confidence level for the electron and muon channels combined. Gauge bosons with a mass below 6.0 TeV and 5.1 TeV are excluded in the electron and muon channels, respectively, in a model with a resonance that has couplings to fermions identical to those of the Standard Model $W$ boson. Cross-section limits are also provided for resonances with several fixed $\Gamma / m$ values in the range between 1% and 15%. Model-independent limits are derived in single-bin signal regions defined by a varying minimum transverse mass threshold. The resulting visible cross-section upper limits range between 4.6 (15) pb and 22 (22) ab as the threshold increases from 130 (110) GeV to 5.1 (5.1) TeV in the electron (muon) channel.
Transverse mass distribution for events satisfying all selection criteria in the electron channel.
Transverse mass distribution for events satisfying all selection criteria in the muon channel.
Upper limits at the 95% CL on the cross section for SSM $W^\prime$ production and decay to the electron+neutrino channel as a function of the $W^\prime$ pole mass.
A search for supersymmetry in events with large missing transverse momentum, jets, and at least one hadronically decaying $\tau$-lepton is presented. Two exclusive final states with either exactly one or at least two $\tau$-leptons are considered. The analysis is based on proton-proton collisions at $\sqrt{s}$ = 13 TeV corresponding to an integrated luminosity of 36.1 fb$^{-1}$ delivered by the Large Hadron Collider and recorded by the ATLAS detector in 2015 and 2016. No significant excess is observed over the Standard Model expectation. At 95% confidence level, model-independent upper limits on the cross section are set and exclusion limits are provided for two signal scenarios: a simplified model of gluino pair production with $\tau$-rich cascade decays, and a model with gauge-mediated supersymmetry breaking (GMSB). In the simplified model, gluino masses up to 2000 GeV are excluded for low values of the mass of the lightest supersymmetric particle (LSP), while LSP masses up to 1000 GeV are excluded for gluino masses around 1400 GeV. In the GMSB model, values of the supersymmetry-breaking scale are excluded below 110 TeV for all values of $\tan\beta$ in the range $2 \leq \tan\beta \leq 60$, and below 120 TeV for $\tan\beta>30$.
1$\tau$ Compressed SR eff.
1$\tau$ MediumMass SR eff.
2$\tau$ Compressed SR eff.
A search for heavy neutral Higgs bosons and $Z^{\prime}$ bosons is performed using a data sample corresponding to an integrated luminosity of 36.1 fb$^{-1}$ from proton-proton collisions at $\sqrt{s}$ = 13 TeV recorded by the ATLAS detector at the LHC during 2015 and 2016. The heavy resonance is assumed to decay to $\tau^+\tau^-$ with at least one tau lepton decaying to final states with hadrons and a neutrino. The search is performed in the mass range of 0.2-2.25 TeV for Higgs bosons and 0.2-4.0 TeV for $Z^{\prime}$ bosons. The data are in good agreement with the background predicted by the Standard Model. The results are interpreted in benchmark scenarios. In the context of the hMSSM scenario, the data exclude $\tan\beta > 1.0$ for $m_A$ = 0.25 TeV and $\tan\beta > 42$ for $m_A$ = 1.5 TeV at the 95% confidence level. For the Sequential Standard Model, $Z^{\prime}_\mathrm{SSM}$ with $m_{Z^{\prime}} < 2.42$ TeV is excluded at 95% confidence level, while $Z^{\prime}_\mathrm{NU}$ with $m_{Z^{\prime}} < 2.25$ TeV is excluded for the non-universal $G(221)$ model that exhibits enhanced couplings to third-generation fermions.
Observed and predicted mTtot distribution in the b-veto category of the 1l1tau_h channel. Despite listing this as an exclusive final state (as there must be no b-jets), there is no explicit selection on the presence of additional light-flavour jets. Please note that the bin content is divided by the bin width in the paper figure, but not in the HepData table. In the paper, the first bin is cut off at 60 GeV for aesthetics but contains underflows down to 50 GeV as in the HepData table. The last bin includes overflows. The combined prediction for A and H bosons with masses of 300, 500 and 800 GeV and $\tan\beta$ = 10 in the hMSSM scenario are also provided.
Observed and predicted mTtot distribution in the b-tag category of the 1l1tau_h channel. Despite listing this as an exclusive final state (as there must be at least one b-jets), there is no explicit selection on the presence of additional light-flavour jets. Please note that the bin content is divided by the bin width in the paper figure, but not in the HepData table. In the paper, the first bin is cut off at 60 GeV for aesthetics but contains underflows down to 50 GeV as in the HepData table. The last bin includes overflows. The combined prediction for A and H bosons with masses of 300, 500 and 800 GeV and $\tan\beta$ = 10 in the hMSSM scenario are also provided.
Observed and predicted mTtot distribution in the b-veto category of the 2tau_h channel. Despite listing this as an exclusive final state (as there must be no b-jets), there is no explicit selection on the presence of additional light-flavour jets. Please note that the bin content is divided by the bin width in the paper figure, but not in the HepData table. The last bin includes overflows. The combined prediction for A and H bosons with masses of 300, 500 and 800 GeV and $\tan\beta$ = 10 in the hMSSM scenario are also provided.
The results of a search for new heavy $W^\prime$ bosons decaying to an electron or muon and a neutrino using proton-proton collision data at a centre-of-mass energy of $\sqrt{s} = 13$ TeV are presented. The dataset was collected in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider and corresponds to an integrated luminosity of 36.1 fb$^{-1}$. As no excess of events above the Standard Model prediction is observed, the results are used to set upper limits on the $W^\prime$ boson cross-section times branching ratio to an electron or muon and a neutrino as a function of the $W^\prime$ mass. Assuming a $W^\prime$ boson with the same couplings as the Standard Model $W$ boson, $W^\prime$ masses below 5.1 TeV are excluded at the 95% confidence level.
Transverse mass distribution for events satisfying all selection criteria in the electron channel.
Transverse mass distribution for events satisfying all selection criteria in the muon channel.
Upper limits at the 95% CL on the cross section for SSM W' production and decay to the electron+neutrino channel as a function of the W' pole mass.
Detailed measurements of $t$-channel single top-quark production are presented. They use 20.2 fb$^{-1}$ of data collected by the ATLAS experiment in proton-proton collisions at a centre-of-mass energy of 8 TeV at the LHC. Total, fiducial and differential cross-sections are measured for both top-quark and top-antiquark production. The fiducial cross-section is measured with a precision of 5.8 % (top quark) and 7.8 % (top antiquark), respectively. The total cross-sections are measured to be $\sigma_{\mathrm{tot}}(tq) = 56.7^{+4.3}_{-3.8}\;$pb for top-quark production and $\sigma_{\mathrm{tot}}(\bar{t}q) = 32.9^{+3.0}_{-2.7}\;$pb for top-antiquark production, in agreement with the Standard Model prediction. In addition, the ratio of top-quark to top-antiquark production cross-sections is determined to be $R_t=1.72 \pm 0.09$, with an improved relative precision of 4.9 % since several systematic uncertainties cancel in the ratio. The differential cross-sections as a function of the transverse momentum and rapidity of both the top quark and the top antiquark are measured at both the parton and particle levels. The transverse momentum and rapidity differential cross-sections of the accompanying jet from the $t$-channel scattering are measured at particle level. All measurements are compared to various Monte Carlo predictions as well as to fixed-order QCD calculations where available.
Predicted and observed event yields for the signal region (SR). The multijet background prediction is obtained from a binned maximum-likelihood fit to the $E_{\mathrm{T}}^{\mathrm{miss}}$ distribution. All the other predictions are derived using theoretical cross-sections, given for the backgrounds in Sect. 6 and for the signal in Sect. 1. The quoted uncertainties are in the predicted cross-sections or in the number of multijet events, in case of the multijet process.
Definition of the fiducial phase space.
The seven input variables to the NN ordered by their discriminating power. The jet that is not $b$-tagged is referred to as $\textit{untagged}~$jet.
Two searches for new phenomena in final states containing a same-flavour opposite-lepton (electron or muon) pair, jets, and large missing transverse momentum are presented. These searches make use of proton--proton collision data, collected during 2015 and 2016 at a centre-of-mass energy $\sqrt{s}=13$ TeV by the ATLAS detector at the Large Hadron Collider, which correspond to an integrated luminosity of 14.7 fb$^{-1}$. Both searches target the pair production of supersymmetric particles, squarks or gluinos, which decay to final states containing a same-flavour opposite-sign lepton pair via one of two mechanisms: a leptonically decaying Z boson in the final state, leading to a peak in the dilepton invariant-mass distribution around the Z boson mass; and decays of neutralinos (e.g. $\tilde{\chi}_2^0 \rightarrow \ell^+\ell^- \tilde{\chi}_1^0$), yielding a kinematic endpoint in the dilepton invariant-mass spectrum. The data are found to be consistent with the Standard Model expectation. Results are interpreted in simplified models of gluino-pair (squark-pair) production, and provide sensitivity to gluinos (squarks) with masses as large as 1.70 TeV (980 GeV).
Dilepton invariant mass distribution in SRZ.
Dilepton transverse momentum distribution in SRZ.
Missing transverse momentum distribution in SRZ.
A search for supersymmetry in events with large missing transverse momentum, jets, and at least one hadronically decaying tau lepton has been performed using 3.2 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV recorded by the ATLAS detector at the Large Hadron Collider in 2015. Two exclusive final states are considered, with either exactly one or at least two tau leptons. No excess over the Standard Model prediction is observed in the data. Results are interpreted in the context of gauge-mediated supersymmetry breaking and a simplified model of gluino pair production with tau-rich cascade decays, substantially improving on previous limits. In the GMSB model considered, supersymmetry-breaking scale ($\Lambda$) values below 92 TeV are excluded at the 95% confidence level, corresponding to gluino masses below 2000 GeV. For large values of $\tan\beta$, values of $\Lambda$ up to 107 TeV and gluino masses up to 2300 GeV are excluded. In the simplified model, gluino masses are excluded up to 1570 GeV for neutralino masses around 100 GeV. Neutralino masses up to 700 GeV are excluded for all gluino masses between 800 GeV and 1500 GeV, while the strongest exclusion of 750 GeV is achieved for gluino masses around 1400 GeV.
mTtau distributions for "extended SR selections" of the 1 tau channel, for the Compressed SR selection without the mTtau > 80 GeV requirement. The last bin includes overflow events. Uncertainties are statistical only. Signal predictions are overlaid for several benchmark models, normalised to their predicted cross sections. For the simplified model, "LM" refers to a low mass splitting, or compressed scenario, with m(gluino)=665 GeV and m(neutralino)=585 GeV; "MM" stands for a medium mass splitting, with m(gluino)=1145 GeV and m(neutralino)=265 GeV; "HM" denotes a high mass splitting scenario, with m(gluino)=1305 GeV and m(neutralino)=105 GeV.
mTtau distributions for "extended SR selections" of the 1 tau channel, for the Medium Mass SR selection without the mTtau > 200 GeV requirement. The last bin includes overflow events. Uncertainties are statistical only. Signal predictions are overlaid for several benchmark models, normalised to their predicted cross sections. For the simplified model, "LM" refers to a low mass splitting, or compressed scenario, with m(gluino)=665 GeV and m(neutralino)=585 GeV; "MM" stands for a medium mass splitting, with m(gluino)=1145 GeV and m(neutralino)=265 GeV; "HM" denotes a high mass splitting scenario, with m(gluino)=1305 GeV and m(neutralino)=105 GeV.
mTtau distributions for "extended SR selections" of the 1 tau channel, for the High Mass SR selection without the mTtau > 200 GeV requirement. The last bin includes overflow events. Uncertainties are statistical only. Signal predictions are overlaid for several benchmark models, normalised to their predicted cross sections. For the simplified model, "LM" refers to a low mass splitting, or compressed scenario, with m(gluino)=665 GeV and m(neutralino)=585 GeV; "MM" stands for a medium mass splitting, with m(gluino)=1145 GeV and m(neutralino)=265 GeV; "HM" denotes a high mass splitting scenario, with m(gluino)=1305 GeV and m(neutralino)=105 GeV.