Rare Decays of $B^{0}_{(s)}$ Mesons to Muon Pairs with the ATLAS Detector (Run 1)

The large amount of Heavy Flavor data collected by the ATLAS experiment at the LHC is potentially sensitive to New Physics, which could be evident in processes that are naturally suppressed in the Standard Model. With the full sample of data (Run 1) collected by the ATLAS detector at 7 and 8~TeV proton-proton collisions, the upper limit on the branching fraction of the $B^{0}\to\mu^{+}\mu^{-}$ decay is set at ${\cal B}(B^{0}\to\mu^{+}\mu^{-}) < 4.2\times 10^{-10}$ at 95% confidence level. For the $B^{0}_{s}$, the branching fraction ${\cal B}(B^{0}_{s}\to\mu^{+}\mu^{-}) = \left(0.9^{+1.1}_{-0.8}\right)\times 10^{-9}$ is obtained. The results are consistent with the Standard Model expectations and other available measurements.