Search for low-mass charged Higgs bosons at CMS

Various extensions of the standard model (SM) invoke the presence of more than one Higgs doublet in the SM Lagrangian. In particular, the two-Higgs doublet model assumes the presence of an additional $SU(2)_{L}$ complex doublet. We are looking for $H^{\pm}$ in the top-quark pair production process, where one top quark decays to a charged Higgs boson and a bottom quark, and the other to a $W$ boson and a bottom quark. The charged Higgs boson further decays into a charm and a strange quark, and the $W$ boson decays to a charged lepton and a neutrino. The search for the charged Higgs boson has been carried out for an $H^{\pm}$ mass range from 80 to 160 GeV. We will discuss the final results published using the 2016 data sample and the new developments in the analysis method for the analysis of full Run-2 data recorded by the CMS experiment at the LHC.