ATLAS discovery potential for a heavy charged Higgs boson

Abstract

The sensitivity of the ATLAS detector to the discovery of a heavy charged Higgs boson is presented. Assuming a heavy SUSY spectrum, the most promising channels above the top quark mass are $H^\pm\to tb$ and $H^\pm\toτ^\pmν_τ$ which provide coverage in the low and high $\tanβ$ regions up to $\sim 600$ GeV. The achievable precisions on the charged Higgs mass and $\tanβ$ determination are also discussed. The $H^\pm\to W^\pm h^0$ channel, though restricted to a small MSSM parameter space, shows a viable signal in NMSSM where the parameter space is less constrained. The observation of the channel $H^-\toτ^-_Lν_τ+ c.c.$ may constitute a distinctive evidence for models with singlet neutrinos in large extra dimensions.