Abstract

Results are reported from a search for supersymmetric particles in the final state with multiple jets and large missing transverse momentum. The search uses a sample of proton-proton collisions at sqrt{s} = 13 TeV collected with the CMS detector in 2016–2018, corresponding to an integrated luminosity of 137 fb−1, representing essentially the full LHC Run 2 data sample. The analysis is performed in a four-dimensional search region defined in terms of the number of jets, the number of tagged bottom quark jets, the scalar sum of jet transverse momenta, and the magnitude of the vector sum of jet transverse momenta. No significant excess in the event yield is observed relative to the expected background contributions from standard model processes. Limits on the pair production of gluinos and squarks are obtained in the framework of simplified models for supersymmetric particle production and decay processes. Assuming the lightest supersymmetric particle to be a neutralino, lower limits on the gluino mass as large as 2000 to 2310 GeV are obtained at 95% confidence level, while lower limits on the squark mass as large as 1190 to 1630 GeV are obtained, depending on the production scenario.

Highlights

  • Background evaluationThe evaluation of the standard model (SM) backgrounds is primarily based on data control regions (CRs)

  • The basic approach of the analysis involves defining search regions in a four-dimensional space specified by key event variables that characterize the topology and kinematics of the events: the total number of jets (Njet), the number of tagged b jets (Nb-jet), the scalar sum of jet pT (HT), and the magnitude of the vector pT sum of the jets (HTmiss)

  • In each of the 174 analysis bins, the background from SM processes is evaluated using event yields measured in corresponding control samples in the data, in conjunction with correction factors obtained from Monte Carlo (MC) simulated event samples

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Summary

Analysis methodology

The basic approach of the analysis involves defining search regions in a four-dimensional space specified by key event variables that characterize the topology and kinematics of the events: the total number of jets (Njet), the number of tagged b jets (Nb-jet), the scalar sum of jet pT (HT), and the magnitude of the vector pT sum of the jets (HTmiss). The principal sources of background arise from several SM processes: production of a top quark, either through top quark-antiquark (tt) pair production or, less often, a single top quark; production of an on- or off-massshell W or Z boson (W+jets and Z+jets events, respectively); and production of multijet events through quantum chromodynamics (QCD) processes. Both top quark and W+jets events can exhibit significant HTmiss and contribute to the background if a W boson decays to a neutrino and an undetected or out-of-acceptance charged lepton, including. T2qq models are the same as T2tt except with bottom squarks and quarks, or light-flavored squarks and quarks, respectively, in place of the top squarks and quarks

Detector and trigger
Event reconstruction
Event selection and search regions
Simulated event samples
Background evaluation
14 Single1l6epton 18 tt
Background from QCD events
Signal systematic uncertainties
Results
10 Summary
A Numerical results for the full set of search bins
B Aggregate search bins
Full Text
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