B→sll¯in the minimal supergravity model

Abstract

The $b\ensuremath{\rightarrow}{\mathrm{sl}}^{+}{l}^{\ensuremath{-}}$ process is studied in the minimal supergravity model in detail. Taking into account the long-distance contributions from the $c\overline{c}$ resonances, we calculate the branching ratio and the lepton forward-backward asymmetry in this model. We find that there is a strong correlation between the branching ratios of $b\ensuremath{\rightarrow}s\ensuremath{\gamma}$ and $b\ensuremath{\rightarrow}{\mathrm{sl}}^{+}{l}^{\ensuremath{-}}$ processes and that the interference effect can change the $b\ensuremath{\rightarrow}{\mathrm{sl}}^{+}{l}^{\ensuremath{-}}$ branching ratio in the off-resonance regions by up to \ifmmode\pm\else\textpm\fi{}15% depending on the relative phase between the long- and short-distance contributions. Using various phenomenological constraints including the branching ratio of $b\ensuremath{\rightarrow}s\ensuremath{\gamma}$, we show that there are regions in the parameter space where the branching ratio of $b\ensuremath{\rightarrow}{\mathrm{sl}}^{+}{l}^{\ensuremath{-}}$ is enhanced by about 50% compared to the standard model (SM). We also show that the branching ratio of $b\ensuremath{\rightarrow}s\ensuremath{\nu}\overline{\ensuremath{\nu}}$ is reduced at most by 10% from the SM prediction.