Two related searches for phenomena beyond the standard model (BSM) are performed using events with hadronic jets and significant transverse momentum imbalance. The results are based on a sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment at the LHC in 2016-2018 and corresponding to an integrated luminosity of 137 fb$^{-1}$. The first search is inclusive, based on signal regions defined by the hadronic energy in the event, the jet multiplicity, the number of jets identified as originating from bottom quarks, and the value of the kinematic variable $M_\mathrm{T2}$ for events with at least two jets. For events with exactly one jet, the transverse momentum of the jet is used instead. The second search looks in addition for disappearing tracks produced by BSM long-lived charged particles that decay within the volume of the tracking detector. No excess event yield is observed above the predicted standard model background. This is used to constrain a range of BSM models that predict the following: the pair production of gluinos and squarks in the context of supersymmetry models conserving $R$-parity, with or without intermediate long-lived charginos produced in the decay chain; the resonant production of a colored scalar state decaying to a massive Dirac fermion and a quark; or the pair production of scalar and vector leptoquarks each decaying to a neutrino and a top, bottom, or light-flavor quark. In most of the cases, the results obtained are the most stringent constraints to date.
Predictions and observations for signal regions with $H_\mathrm{T} \geq 1500$ GeV and $N_\mathrm{j}<7$
Exclusion limits at 95% CL for direct gluino pair production, where the gluinos decay to light-flavor quarks and either the lightest neutralino, or the lightest chargino, and the chargino mass is O(100) MeV greater than the neutralino's mass. The chargino's lifetime is varied from $c\tau_{0} = 5$ to 1000 cm while the gluino mass is fixed to 1600 GeV and the neutralino's mass is fixed to 1575 GeV. Signal cross sections are calculated at approximately NNLO+NNLL order in $\alpha_S$.
Exclusion limits at 95% CL for direct squark pair production, where the squarks decay to light-flavor quarks and either the lightest neutralino, or the lightest chargino, and the chargino mass is O(100) MeV greater than the neutralino's mass. The chargino's lifetime is varied from $c\tau_{0} = 5$ to 1000 cm while the squark mass is fixed to 2000 GeV and the neutralino's mass is fixed to 1000 GeV. Signal cross sections are calculated at approximately NNLO+NNLL order in $\alpha_S$, and the eight light squarks' masses are assumed to be degenerate.
A search is presented for a third-generation leptoquark (LQ) coupled exclusively to a $\tau$ lepton and a b quark. The search is based on proton-proton collision data at a center-of-mass energy of 13 TeV recorded with the CMS detector, corresponding to an integrated luminosity of 138 fb$^{-1}$. Events with $\tau$ leptons and a varying number of jets originating from b quarks are considered, targeting the single and pair production of LQs, as well as nonresonant $t$-channel LQ exchange. An excess is observed in the data with respect to the background expectation in the combined analysis of all search regions. For a benchmark LQ mass of 2 TeV and an LQ-b-$\tau$ coupling strength of 2.5, the excess reaches a local significance of up to 2.8 standard deviations. Upper limits at the 95% confidence level are placed on the LQ production cross section in the LQ mass range 0.5-2.3 TeV, and up to 3 TeV for $t$-channel LQ exchange. Leptoquarks are excluded below masses of 1.22-1.88 TeV for different LQ models and varying coupling strengths up to 2.5. The study of nonresonant $\tau\tau$ production through $t$-channel LQ exchange allows lower limits on the LQ mass of up to 2.3 TeV to be obtained.
Postfit distributions of $S_\mathrm{T}^\mathrm{MET}$ in the $\mathrm{e}\mu$ channel of the 0b category for the combined 2016-2018 data set after a simultaneous fit of the background and vector LQ signal to the data. The number of events in each bin are divided by the respective bin width. The last bin includes the overflow.
The paper presents a search for supersymmetric particles produced in proton-proton collisions at $\sqrt{s}=$ 13 TeV and decaying into final states with missing transverse momentum and jets originating from charm quarks. The data were taken with the ATLAS detector at the Large Hadron Collider at CERN from 2015 to 2018 and correspond to an integrated luminosity of 139 fb$^{-1}$. No significant excess of events over the expected Standard Model background expectation is observed in optimized signal regions, and limits are set on the production cross-sections of the supersymmetric particles. Pair production of charm squarks or top squarks, each decaying into a charm quark and the lightest supersymmetric particle $\tilde{\chi}^0_1$, is excluded at 95% confidence level for squarks with masses up to 900 GeV for scenarios where the mass of $\tilde{\chi}^0_1$ is below 50 GeV. Additionally, the production of leptoquarks with masses up to 900 GeV is excluded for the scenario where up-type leptoquarks decay into a charm quark and a neutrino. Model-independent limits on cross-sections and event yields for processes beyond the Standard Model are also reported.
Summary of material in this HEPData record. <br/><br/> Truth Code snippets, SLHA files, Madgraph process cards and UFO files for the leptoquark models are available under "Additional Resources" (purple button on the left). <br/><br/> <b>Contours:</b> <ul> SUSY exclusion limits (best-expected SR combination) <ul> <a href="155678?version=1&table=Contour1">Expected</a> <a href="155678?version=1&table=Contour3">+1$\sigma$</a> <a href="155678?version=1&table=Contour2">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour4">Observed</a> <a href="155678?version=1&table=Contour5">+1$\sigma$</a> <a href="155678?version=1&table=Contour6">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (best-expected SR combination) as a function of $\Delta m(\tilde{t}_1,\tilde{\chi}_1^0)$ <ul> <a href="155678?version=1&table=Contour7">Expected</a> <a href="155678?version=1&table=Contour9">+1$\sigma$</a> <a href="155678?version=1&table=Contour8">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour10">Observed</a> <a href="155678?version=1&table=Contour11">+1$\sigma$</a> <a href="155678?version=1&table=Contour12">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-HM1) <ul> <a href="155678?version=1&table=Contour15">Expected</a> <a href="155678?version=1&table=Contour14">+1$\sigma$</a> <a href="155678?version=1&table=Contour13">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour18">Observed</a> <a href="155678?version=1&table=Contour16">+1$\sigma$</a> <a href="155678?version=1&table=Contour17">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-HM2) <ul> <a href="155678?version=1&table=Contour21">Expected</a> <a href="155678?version=1&table=Contour20">+1$\sigma$</a> <a href="155678?version=1&table=Contour19">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour24">Observed</a> <a href="155678?version=1&table=Contour22">+1$\sigma$</a> <a href="155678?version=1&table=Contour23">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-HM3) <ul> <a href="155678?version=1&table=Contour27">Expected</a> <a href="155678?version=1&table=Contour26">+1$\sigma$</a> <a href="155678?version=1&table=Contour25">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour30">Observed</a> <a href="155678?version=1&table=Contour28">+1$\sigma$</a> <a href="155678?version=1&table=Contour29">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-Comp1) <ul> <a href="155678?version=1&table=Contour33">Expected</a> <a href="155678?version=1&table=Contour32">+1$\sigma$</a> <a href="155678?version=1&table=Contour31">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour36">Observed</a> <a href="155678?version=1&table=Contour34">+1$\sigma$</a> <a href="155678?version=1&table=Contour35">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-Comp2) <ul> <a href="155678?version=1&table=Contour39">Expected</a> <a href="155678?version=1&table=Contour38">+1$\sigma$</a> <a href="155678?version=1&table=Contour37">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour42">Observed</a> <a href="155678?version=1&table=Contour40">+1$\sigma$</a> <a href="155678?version=1&table=Contour41">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-Comp3) <ul> <a href="155678?version=1&table=Contour45">Expected</a> <a href="155678?version=1&table=Contour44">+1$\sigma$</a> <a href="155678?version=1&table=Contour43">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour48">Observed</a> <a href="155678?version=1&table=Contour46">+1$\sigma$</a> <a href="155678?version=1&table=Contour47">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-Comp-1c) <ul> <a href="155678?version=1&table=Contour50">Expected</a> <a href="155678?version=1&table=Contour49">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (scan over branching fraction for $m(\tilde{\chi}_1^0)=1$ GeV) <ul> <a href="155678?version=1&table=Contour51">Expected</a> <a href="155678?version=1&table=Contour53">+1$\sigma$</a> <a href="155678?version=1&table=Contour52">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour54">Observed</a> <a href="155678?version=1&table=Contour55">+1$\sigma$</a> <a href="155678?version=1&table=Contour56">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (scan over branching fraction for $m(\tilde{\chi}_1^0)=200$ GeV) <ul> <a href="155678?version=1&table=Contour57">Expected</a> <a href="155678?version=1&table=Contour59">+1$\sigma$</a> <a href="155678?version=1&table=Contour58">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour60">Observed</a> <a href="155678?version=1&table=Contour61">+1$\sigma$</a> <a href="155678?version=1&table=Contour62">-1$\sigma$</a> <br/> </ul> $\mathrm{LQ}^\mathrm{u}_{21}$ exclusion limits <ul> <a href="155678?version=1&table=Contour65">Expected</a> <a href="155678?version=1&table=Contour64">+1$\sigma$</a> <a href="155678?version=1&table=Contour63">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour68">Observed</a> <a href="155678?version=1&table=Contour66">+1$\sigma$</a> <a href="155678?version=1&table=Contour67">-1$\sigma$</a> <br/> </ul> $\mathrm{LQ}^\mathrm{u}_{22}$ exclusion limits <ul> <a href="155678?version=1&table=Contour71">Expected</a> <a href="155678?version=1&table=Contour70">+1$\sigma$</a> <a href="155678?version=1&table=Contour69">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour74">Observed</a> <a href="155678?version=1&table=Contour72">+1$\sigma$</a> <a href="155678?version=1&table=Contour73">-1$\sigma$</a> <br/> </ul> </ul> <b>Cross-section upper limits:</b> <ul> SUSY signals (best-expected SR combination): <a href="155678?version=1&table=Cross-sectionupperlimit1">Observed</a> <br/> $\mathrm{LQ}^\mathrm{u}_{21}$ (combined High-Mass SRs): <a href="155678?version=1&table=Cross-sectionupperlimit2">Observed</a> <br/> $\mathrm{LQ}^\mathrm{u}_{22}$ (combined High-Mass SRs): <a href="155678?version=1&table=Cross-sectionupperlimit3">Observed</a> <br/> $U(1)$ pair (min) (combined High-Mass SRs): <a href="155678?version=1&table=Cross-sectionupperlimit6">Expected</a> <a href="155678?version=1&table=Cross-sectionupperlimit5">+1$\sigma$</a> <a href="155678?version=1&table=Cross-sectionupperlimit4">-1$\sigma$</a> <a href="155678?version=1&table=Cross-sectionupperlimit7">Observed</a> <br/> $U(1)$ pair (YM) (combined High-Mass SRs): <a href="155678?version=1&table=Cross-sectionupperlimit10">Expected</a> <a href="155678?version=1&table=Cross-sectionupperlimit9">+1$\sigma$</a> <a href="155678?version=1&table=Cross-sectionupperlimit8">-1$\sigma$</a> <a href="155678?version=1&table=Cross-sectionupperlimit11">Observed</a> <br/> </ul> <b>Signal region distributions:</b> <ul> <a href="155678?version=1&table=SRdistribution2">$E_\mathrm{T}^\mathrm{miss}$ Sig. in SR-HM1</a> <br/> <a href="155678?version=1&table=SRdistribution3">$m_\mathrm{T}^\mathrm{min}(c)$ in SR-HM2</a> <br/> <a href="155678?version=1&table=SRdistribution4">$R_\mathrm{ISR}$ in SR-Comp1</a> <br/> <a href="155678?version=1&table=SRdistribution5">$R_\mathrm{ISR}$ in SR-Comp2</a> <br/> <a href="155678?version=1&table=SRdistribution6">$R_\mathrm{ISR}$ in SR-Comp3</a> <br/> <a href="155678?version=1&table=SRdistribution1">$R_\mathrm{ISR}$ in SR-Comp-1c</a> <br/> </ul> <b>Acceptances:</b> <ul> SUSY signals: <a href="155678?version=1&table=Acceptance2">SR-HM1</a> <a href="155678?version=1&table=Acceptance3">SR-HM2</a> <a href="155678?version=1&table=Acceptance4">SR-HM3</a> <a href="155678?version=1&table=Acceptance5">SR-HM-Disc</a> <a href="155678?version=1&table=Acceptance6">SR-Comp1</a> <a href="155678?version=1&table=Acceptance7">SR-Comp2</a> <a href="155678?version=1&table=Acceptance8">SR-Comp3</a> <a href="155678?version=1&table=Acceptance1">SR-Comp-1c</a> <br/> $\mathrm{LQ}^\mathrm{u}_{21}$: <a href="155678?version=1&table=Acceptance9">SR-HM1</a> <a href="155678?version=1&table=Acceptance10">SR-HM2</a> <a href="155678?version=1&table=Acceptance11">SR-HM3</a> <a href="155678?version=1&table=Acceptance12">SR-HM-Disc</a> <br/> $\mathrm{LQ}^\mathrm{u}_{22}$: <a href="155678?version=1&table=Acceptance13">SR-HM1</a> <a href="155678?version=1&table=Acceptance14">SR-HM2</a> <a href="155678?version=1&table=Acceptance15">SR-HM3</a> <a href="155678?version=1&table=Acceptance16">SR-HM-Disc</a> <br/> $U(1)$ pair (min): <a href="155678?version=1&table=Acceptance17">SR-HM1</a> <a href="155678?version=1&table=Acceptance18">SR-HM2</a> <a href="155678?version=1&table=Acceptance19">SR-HM3</a> <a href="155678?version=1&table=Acceptance20">SR-HM-Disc</a> <br/> $U(1)$ pair (YM): <a href="155678?version=1&table=Acceptance21">SR-HM1</a> <a href="155678?version=1&table=Acceptance22">SR-HM2</a> <a href="155678?version=1&table=Acceptance23">SR-HM3</a> <a href="155678?version=1&table=Acceptance24">SR-HM-Disc</a> <br/> </ul> <b>Efficiencies:</b> <ul> $U(1)$ pair (min): <a href="155678?version=1&table=Efficiency1">SR-HM1</a> <a href="155678?version=1&table=Efficiency2">SR-HM2</a> <a href="155678?version=1&table=Efficiency3">SR-HM3</a> <a href="155678?version=1&table=Efficiency4">SR-HM-Disc</a> <br/> $U(1)$ pair (YM): <a href="155678?version=1&table=Efficiency5">SR-HM1</a> <a href="155678?version=1&table=Efficiency6">SR-HM2</a> <a href="155678?version=1&table=Efficiency7">SR-HM3</a> <a href="155678?version=1&table=Efficiency8">SR-HM-Disc</a> <br/> </ul> <b>Acceptance times efficiency:</b> <ul> SUSY signals: <a href="155678?version=1&table=Acceptancetimesefficiency2">SR-HM1</a> <a href="155678?version=1&table=Acceptancetimesefficiency3">SR-HM2</a> <a href="155678?version=1&table=Acceptancetimesefficiency4">SR-HM3</a> <a href="155678?version=1&table=Acceptancetimesefficiency5">SR-HM-Disc</a> <a href="155678?version=1&table=Acceptancetimesefficiency6">SR-Comp1</a> <a href="155678?version=1&table=Acceptancetimesefficiency7">SR-Comp2</a> <a href="155678?version=1&table=Acceptancetimesefficiency8">SR-Comp3</a> <a href="155678?version=1&table=Acceptancetimesefficiency1">SR-Comp-1c</a> <br/> $\mathrm{LQ}^\mathrm{u}_{21}$: <a href="155678?version=1&table=Acceptancetimesefficiency9">SR-HM1</a> <a href="155678?version=1&table=Acceptancetimesefficiency10">SR-HM2</a> <a href="155678?version=1&table=Acceptancetimesefficiency11">SR-HM3</a> <a href="155678?version=1&table=Acceptancetimesefficiency12">SR-HM-Disc</a> <br/> $\mathrm{LQ}^\mathrm{u}_{22}$: <a href="155678?version=1&table=Acceptancetimesefficiency13">SR-HM1</a> <a href="155678?version=1&table=Acceptancetimesefficiency14">SR-HM2</a> <a href="155678?version=1&table=Acceptancetimesefficiency15">SR-HM3</a> <a href="155678?version=1&table=Acceptancetimesefficiency16">SR-HM-Disc</a> <br/> $U(1)$ pair (min): <a href="155678?version=1&table=Acceptancetimesefficiency17">SR-HM1</a> <a href="155678?version=1&table=Acceptancetimesefficiency18">SR-HM2</a> <a href="155678?version=1&table=Acceptancetimesefficiency19">SR-HM3</a> <a href="155678?version=1&table=Acceptancetimesefficiency20">SR-HM-Disc</a> <br/> $U(1)$ pair (YM): <a href="155678?version=1&table=Acceptancetimesefficiency21">SR-HM1</a> <a href="155678?version=1&table=Acceptancetimesefficiency22">SR-HM2</a> <a href="155678?version=1&table=Acceptancetimesefficiency23">SR-HM3</a> <a href="155678?version=1&table=Acceptancetimesefficiency24">SR-HM-Disc</a> <br/> </ul> <b>Cutflow:</b> <ul> SUSY benchmarks: <a href="155678?version=1&table=Cutflow5">SR-HM1</a> <a href="155678?version=1&table=Cutflow6">SR-HM2</a> <a href="155678?version=1&table=Cutflow7">SR-HM3</a> <a href="155678?version=1&table=Cutflow8">SR-HM-Disc</a> <a href="155678?version=1&table=Cutflow2">SR-Comp1</a> <a href="155678?version=1&table=Cutflow3">SR-Comp2</a> <a href="155678?version=1&table=Cutflow4">SR-Comp3</a> <a href="155678?version=1&table=Cutflow1">SR-Comp-1c</a> <br/> LQ benchmarks: <a href="155678?version=1&table=Cutflow9">SR-HM1</a> <a href="155678?version=1&table=Cutflow10">SR-HM2</a> <a href="155678?version=1&table=Cutflow11">SR-HM3</a> <a href="155678?version=1&table=Cutflow12">SR-HM-Disc</a> <br/> </ul>
Observed exclusion limit $(+1\sigma)$ at 95% CL for pair production of top squarks decaying to charm quarks and neutralinos when only considering SR-HM2.
Acceptance across the $\mathrm{LQ}^\mathrm{u}_{22}$ signal grid for SR-HM1.
Forum