The tan(beta) - M_H^\pm bound from inclusive semi-tauonic B-decays in the MSSM

Abstract

We compute the O(alpha_s) SUSY-QCD corrections to the W and charged Higgs mediated inclusive semi-tauonic B-decay, B->tau antineutrino_tau X. Combining the SUSY contribution with the SM result obtained from the heavy quark effective field theory, plus ordinary QCD corrections, we find that the allowed region in the (tan(beta),M_H^\pm)-plane could be significantly modified by the short-distance supersymmetric effects. Since the sensitivity to the SUSY parameters other than mu (the higgsino mixing mass) is rather low, the following effective bound emerges for mu<0 at the 2 sigma level: tan(beta)~< 0.43 (M_H^\pm/GeV). Remarkably, for mu>0 there could be no bound at all. Finally, we provide a combined (tan(beta,M_H^\pm) exclusion plot using our B-meson results together with the recent data from top quark decays.