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Compact Muon Solenoid
LHC, CERN

CMS-PAS-EXO-21-014
Search for long-lived particles in pp collision events with delayed trackless jets at $ \sqrt{s} = $ 13 TeV
Abstract: A search for long-lived particles decaying in the outer regions of the CMS silicon tracker or in the calorimeters is presented. The data sample consists of 138 fb$ ^{-1} $ of proton-proton collisions at $ \sqrt{s} = $ 13 TeV, recorded at the LHC in 2016--2018. A novel technique, using trackless and delayed jet information combined in a deep neural network discriminator, is employed to identify decays of long-lived particles. The results are interpreted in a simplified model of chargino-neutralino production, where the neutralino is the next-to-lightest supersymmetric particle, is long-lived, and decays to a gravitino and either a Higgs or Z boson. This search is most sensitive to neutralino proper decay lengths of $ \approx $1 $ \mathrm{m} $, for which neutralino masses from up to 1180 GeV are excluded at 95% confidence level.
CMS Publications
Compact Muon Solenoid
LHC, CERN