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

Abstract

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 $m_{H^{\pm}} > m_t$ and $3 \lsim tan(beta) \lsim 10$, where identification of the $H^{\pm}$ via other decay modes has proven to be ineffective. Searching for means to plug this hole, we simulate the decays $H^{\pm} --> {\tildeχ}_1^{\pm} {\tildeχ}_1^0$ and $H^{\pm} --> {\tildeχ}_1^{\pm} {\tildeχ}_2^0, {\tildeχ}_1^{\pm} {\tildeχ}_3^0$ --- 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 $M_2$, $μ$, and slepton masses), it does fill at least some of the void left by previous investigations.