$B_{s,d}^0\rightarrow l^+l^-$ in the minimal gauged $(B-L)$   supersymmetry
  Complete expressions of effective Hamilton for $b\rightarrow sl^+l^-\;(l=\mu,\;\tau)$ are derived in the framework of minimal supersymmetric extension of the standard model with local $B-L$ gauge symmetry. With some assumptions on parameters of the model, a numerical analysis of the supersymmetric contributions to the branching ratios of $B_s^0\rightarrow l^+l^-\;(l=\mu,\;\tau)$ is presented. 
Tai-Fu Feng, Yu-Li Yan, Hai-Bin Zhang, Shu-Min Zhao
hep-ph