Search for singly and pair-produced leptoquarks coupling to third-generation fermions in proton-proton collisions at s=13 TeV


Sirunyan A., Tumasyan A., Adam W., Bergauer T., Dragicevic M., Erö J., ...More

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol.819, 2021 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 819
  • Publication Date: 2021
  • Doi Number: 10.1016/j.physletb.2021.136446
  • Title of Journal : Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
  • Keywords: CMS, Search for new physics, Leptoquarks, MODEL, EXTENSION, INVARIANT

Abstract

© 2021 The Author(s)A search for leptoquarks produced singly and in pairs in proton-proton collisions is presented. We consider the leptoquark (LQ) to be a scalar particle of charge −1/3e coupling to a top quark plus a tau lepton (tτ) or a bottom quark plus a neutrino (bν), or a vector particle of charge +2/3e, coupling to tν or bτ. These choices are motivated by models that can explain a series of anomalies observed in the measurement of B meson decays. In this analysis the signatures tτνb and tτν are probed, using data recorded by the CMS experiment at the CERN LHC at s=13 TeV and that correspond to an integrated luminosity of 137 fb−1. These signatures have not been previously explored in a dedicated search. The data are found to be in agreement with the standard model prediction. Lower limits at 95% confidence level are set on the LQ mass in the range 0.98–1.73 TeV, depending on the LQ spin and its coupling λ to a lepton and a quark, and assuming equal couplings for the two LQ decay modes considered. These are the most stringent constraints to date on the existence of leptoquarks in this scenario.