Observability of heavy charged MSSM Higgs bosons in the $H^{+-} \to tb$ decay in CMS

The prospects to discover a heavy charged MSSM Higgs boson in the Hrightward arrowtb decay channel are presented, with the tagging of three b quarks. This analysis includes the most recent signal cross section values, a dedicated simulation of the large ttmacron+jets background, a study of the trigger acceptance and the influence of the systematic uncertainties on the background cross section. The discovery reach is given in the MSSM parameter space, and it is concluded that, with the present analysis, no visibility is left.