Towards testing a two-Higgs-doublet model with maximal CP symmetry at the LHC: construction of a Monte Carlo event generator

Abstract

A Monte Carlo event generator is constructed for a two-Higgs-doublet model with maximal CP symmetry, the MCPM. The model contains five physical Higgs bosons; the ${\rho }^{\prime }$, behaving similarly to the standard-model Higgs boson, two extra neutral bosons $h^{\prime }$ and $h"$, and a charged pair $H^{\pm }$. The special feature of the MCPM is that, concerning the Yukawa couplings, the bosons $h^{\prime }$, $h"$ and $H^{\pm }$ couple directly only to the second generation fermions but with strengths given by the third-generation-fermion masses. Our event generator allows the simulation of the Drell-Yan-type production processes of $h^{\prime }$, $h"$ and $H^{\pm }$ in proton-proton collisions at LHC energies. Also the subsequent leptonic decays of these bosons into the ${\mu }^{+}{\mu }^{-}$, ${\mu }^{+}{\nu }_{\mu }$ and ${\mu }^{-}{\bar{\nu }}_{\mu }$ channels are studied as well as the dominant background processes. We estimate the integrated luminosities needed in $pp$ collisions at center-of-mass energies of 8 TeV and 14 TeV for significant observations of the Higgs bosons $h^{\prime }$, $h"$ and $H^{\pm }$ in these muonic channels.