CHARGED-HIGGS-BOSON AND STAU PHENOMENOLOGY IN THE SIMPLEST R-PARITY BREAKING MODEL

We consider the charged scalar boson phenomenology in the simplest eff ective low-energy R-parity breaking model characterized by a bilinear violation of R-parity in the superpotential. This induces a mixing bet ween staus and the charged Higgs boson. We show that the charged Higgs boson mass can be lower than expected in the MSSM, even before includ ing radiative corrections. We also study the charged scalar boson deca y branching ratios and show that the R-parity-violating decay rates ca n be comparable or even bigger than the R-parity conserving ones. More over, if the stau is the LSP it will have only decays into standard mo del fermions. These features could have important implications for cha rged supersymmetric scalar boson searches at future accelerators. (C) 1998 Elsevier Science B.V.