Charged Higgs Sector with and without R--Parity

Abstract

The simplest way of studying systematically R-parity violating phenomena is by introducing a bilinear term in the superpotential of the type $\epsilon\hat L\hat H_2$, which violates R-parity and lepton number but keep barion number conserved. In its simplest version, this ``$\epsilon$--model'' is a two parameter extension of the MSSM and a one parameter extension of the MSSM--SUGRA. Here we study the charged Higgs sector of the model, which mixes with the stau sector, and compare it with the charged Higgs sector of the MSSM. We demonstrate that $m_{H^{\pm}}$ can be lower than $m_W$ already at tree level, and calculate the production cross section of pairs of charged Higgs and staus. In this model it is possible the mixed production of a charged Higgs and a stau and its production cross section can be sizable. We finally comment about the new R-parity violating decay modes of the charged scalars.