B$_{d/s} \to \mu^{+}\mu^-$ in ATLAS

The ATLAS Experiment has conducted a search for the rare decays of $B_{s}$ and $B_{d}$ into two muons. 25 fb$^{−1}$ of integrated luminosity of proton-proton collisions collected during LHC Run 1 were studied and new results were obtained, as presented in this talk. An upper limit is set on the Bd to mu+mu- branching ratio of $\mathcal{B}(B_{d} \rightarrow \mu^{+}\mu^{-}) < 4.2 \times 10^{−10}$ at 95% confidence level. For $B_{s}$, ATLAS measurement yields the branching ratio $\mathcal B(B_{s} \rightarrow \mu^{+}\mu^{-})=(0.9^{+1.1}_{−0.8}) \times 10^{−9}$. The result is consistent with the Standard Model expectation and other available measurements.