Higgs-boson coupling to charginos in the MSSM at linear colliders

Abstract

We discuss the associated production of a light Higgs boson and a light chargino pair in the process e+e- -> h chi+ chi- in the Minimal Supersymmetric Standard Model (MSSM) at linear colliders (LC) with \sqrt s=500 GeV. This process gives direct informations about the Higgs-boson coupling to light charginos, that cannot be analyzed in decay processes due to phase-space restrictions. We compute total cross sections in the regions of the MSSM parameter space where the process cannot proceed via on-shell production and subsequent decay of either heavier charginos or pseudoscalar Higgs bosons A. Cross sections up to a few 0.1 fb are allowed, making this process potentially detectable at high-luminosity linear colliders. We also compute analytically the final h momentum distributions in the limit of very heavy electron-sneutrino masses.