Signatures of MSSM charged Higgs bosons via chargino-neutralino decay channels at the LHC

We assess the potential of detecting a charged Higgs boson of the MSSM at the LHC via its decays into a chargino and a neutralino. We focus our attention on the region of parameter space with mH± > mt and 3<or∼tanβ<or∼10, where identification of the H± via other decay modes has proven to be ineffective. Searching for means to plug this hole, we simulate the decays H±→χ1±χ10 and H±→ χ1±χ20, χ1±χ30 - the former can yield a single hard lepton (from the chargino decay) while the latter can yield three leptons (from the chargino and neutralino decays). Coupled with the dominant top quark + charged Higgs boson production mode, the resulting signature is one or three hard, isolated leptons, substantial missing transverse momentum and a reconstructed (via a 3-jet invariant mass) top quark. The single lepton channel is swamped by background processes; however, with suitable cuts, a trilepton signal emerges. While such a signal suffers from a low number of surviving events (after cuts) and is dependent on several MSSM input parameters (notably M2, μ, and slepton masses), it does fill at least some of the void left by previous investigations. (orig.)