CMS-PAS-EXO-19-021

CMS-PAS-EXO-19-021
Search for long-lived particles decaying into displaced jets
CMS Collaboration
May 2020

Abstract: An inclusive search for long-lived particles decaying into jets is presented. The search uses a data sample corresponding to an integrated luminosity of 132 fb$^{-1}$ from proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC in 2016, 2017, and 2018. The analysis examines the distinctive topology of displaced tracks and displaced vertices within a dijet system. For a simplified model, where pair-produced long-lived neutral particles decay into quark-antiquark pairs, pair production cross sections larger than 0.07 fb are excluded at 95% confidence level for long-lived particle masses larger than 500 GeV and mean proper decay lengths between 2 and 250 mm. For a model where the standard model Higgs boson decays to two long-lived scalars and then each scalar decays to a quark-antiquark pair, branching fractions larger than 1% can be excluded for mean proper decay lengths between 1 mm and 1 m. A group of supersymmetry models with pair-produced long-lived gluinos or top squarks decaying into different final-state topologies containing displaced jets is also tested. Gluino masses up to 2500 GeV and top squark masses up to 1600 GeV are excluded for mean proper decay lengths between 3 and 300 mm. The best mass bounds reach 2600 GeV for long-lived gluinos and 1800 GeV for long-lived top squarks. These are currently the most restrictive limits on these models.
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; These preliminary results are superseded in this paper, Accepted by PRD. The superseded preliminary plots can be found here.

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