LHCb potential to measure/exclude the branching ratio of the decay $B_s \to mu^{+}mu^{-}$

We present the potential of the LHCb detector to measure/exclude the $B_s \to mu^{+}mu^{-}$ branching ratio in $pp$ collisions at $\sqrt{s}$ = 14 Tev at LHC. LHCb can exclude the interesting region between 10$^{-8}$ and Standard Model predictions with ~0.5 fb$^{-1}$ and to claim 3$\sigma$ (5$\sigma$) observation (discovery) of the Standard Model prediction with ~2 fb$^{-1}$ (~6 fb$^{-1}$ of integrated luminosity.