B-meson dileptonic decays enhanced by supersymmetry with large tanβ

Abstract

We examined the rare decays $B\\to X_s\\ell^+\\ell^-$ and\n$B_s\\to\\ell^+\\ell^-\\gamma$ in the minimal supersymmetric model with large\n$\\tan\\beta$. Taking into account the gluino-loop and neutralino-loop effects,\nwe found that for a large $\\tan\\beta$ the neutral Higgs exchanging diagrams\ncould enhance $Br(B\\to X_s\\tau^+\\tau^-)$ by a factor of 5 and\n$Br(B_s\\to\\tau^+\\tau^-\\gamma)$ by a couple of orders in some part of\nsupersymmetric parameter space allowed by current experiments such as $b\\to\ns\\gamma, B\\to K^{(*)}\\ell^+\\ell^-$ and $B_s\\to\\ell^+\\ell^-$. The\nforward-backward asymmetry and the distributions of differential branching\nratios are also found to differ significantly from the standard model results.\n Such enhanced branching ratios reach the level of $10^{-5}$ and thus might be\nobservable in the new generation of B experiments.\n