Charged Higgs mass bounds from b → sγ in a bilinear R-parity violating model Original Research Article

The experimental measurement of B(b → sγ) imposes important constraints on the charged Higgs boson mass in the MSSM. If squarks are in the few TeV range, the charged Higgs boson mass in the MSSM must satisfy mH± ⪆ 440 GeV. For lighter squarks, then light charged Higgs bosons can be reconciled with B(b → sγ) only if there is also a light chargino. In the MSSM if we impose mχ1± > 90 eV then we need mH± ⪆ 110 GeV. We show that by adding bilinear R-parity violation (BRpV) in the tau sector, these bounds are relaxed. The bound on mH± in the MSSM-BRpV model is ⪆ 340 GeV for the heavy squark case and mH± ⪆ 75 GeV for the case of light squarks. In this case the charged Higgs bosons would be observable at LEP II. The relaxation of the bounds is due mainly to the fact that charged Higgs bosons mix with staus and they contribute importantly to B(b → sγ).