Comprehensive analysis on the light Higgs boson scenario

Abstract

A comprehensive analysis on the light Higgs scenario (LHS) of the minimal supersymmetric standard model is performed in the framework of the nonuniversal Higgs mass model (NUHM). In the LHS, the lightest Higgs boson mass is lighter than 114.4 GeV, and the LEP bound is avoided because the coupling of the lightest Higgs boson with the $Z$ boson can be suppressed if other MSSM Higgs boson masses are also around 100--200 GeV. The NUHM is known to be the simplest framework realizing the LHS with consistent unifications of gaugino and sfermion masses at the grand unified theory scale. All important constraints from collider experiments, flavor-changing processes, and cosmological observations are considered in order to clarify the allowed region of the model parameter space, where the Markov chain Monte Carlo method is used to obtain the region. We show that the region is excluded by current LHC results for the SUSY particle searches. We discuss possible extensions to save the LHS. Even with such extensions, the measurement of ${B}_{s}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ would enable us to test the LHS in the near future.