# CERN Accelerating science

 Thesis Report number CERN-THESIS-2019-257 ; HIG-18-021 Title Search for a charged Higgs Boson at 13 TeV in the CMS experiment at the LHC, CERN Author(s) Verma, Ravindra Kumar (Indian Inst. Tech., Kanpur) Publication 226 p. Thesis note PhD : Indian Inst. Tech., Kanpur : 2019 Thesis supervisor(s) Jain, Pankaj ; Dugad, Shashi Note Presented 27 Dec 2019 Subject category Particle Physics - Experiment Accelerator/Facility, Experiment CERN LHC ; CMS Abstract A search is conducted for a low-mass charged Higgs boson produced in a top quark decay and subsequently decaying into a charm and a strange quark. The data sample was recorded in proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$ by the CMS experiment at the LHC and corresponds to an integrated luminosity of $35.9~\mathrm{fb}^{-1}$. The signal search is conducted in the process of top-quark pair production, where one top quark decays to a bottom quark and a charged Higgs boson, and the other to a bottom quark and a W boson. With the W boson decaying to a charged lepton (electron or muon) and a neutrino, the final state comprises an isolated lepton, missing transverse momentum, and at least four jets, of which two are tagged as b jets. To enhance the search sensitivity, one of the jets originating from the charged Higgs boson is required to satisfy a charm tagging requirement. No significant excess beyond standard model predictions is found in the dijet invariant mass distribution. An upper limit in the range $0.20$$-$$1.65\%$ is set on the branching fraction of the top quark decay to the charged Higgs boson and bottom quark for a Higgs mass between $80$ and $160$ GeV.

Email contact: ravindra.kumar.verma@cern.ch