CMS-PAS-EXO-21-018

CMS-PAS-EXO-21-018
Search for dilepton resonances from decays of (pseudo)scalar bosons produced in association with a massive vector boson or top quark anti-top quark pair at $\sqrt{s}= $ 13 TeV
CMS Collaboration
July 2022

Abstract: A search for beyond the standard model scalar and pseudoscalar bosons that decay into pairs of electrons, muons, or tau leptons is presented. The search probes such new bosons that are produced in association with a W or Z boson, or a top quark anti-top quark pair, in events with with three or four leptons, including hadronic decays of tau leptons. The proton-proton collision dataset used in the analysis is collected by the CMS experiment at the LHC in 2016-2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138 fb$^{-1}$. The observations are consistent with the expectations from standard model processes. Upper limits at 95% confidence level are placed on the product of cross section and branching fraction of such new particles with scalar, pseudoscalar, or Higgs-like couplings. Considering a single production, coupling, and decay scenario at a time, the observations exclude product of cross section and branching fraction values above 50-0.5 fb, 30-0.5 fb and 200-1 fb for new scalar, pseudoscalar, and Higgs-like bosons, respectively, that have a mass in the range 15-350 GeV and exclusively decay into dielectron or dimuon pairs. Similarly, assuming such new bosons exclusively decay into pairs of tau leptons, the product of cross section and branching fraction values above 35-0.004 pb, 80-0.004 pb, and 250-0.008 pb are excluded for scalar, pseudoscalar, and Higgs-like couplings, respectively. These are the most restrictive direct limits in these production and decay modes on an extension of the standard model with scalar or pseudoscalar particles.
Links: CDS record (PDF) ; CADI line (restricted) ; These preliminary results are superseded in this paper, Submitted to PRD. The superseded preliminary plots can be found here.

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