Search for the Decay Bs0→ μμ with the ATLAS Detector

Flavour Changing Neutral Current processes are highly suppressed in the Standard Model(SM), and therefore their study is of particular interest in the search for new physics. The small SM prediction for the branching fraction Br(Bs0→ μμ) (O(10-9)) might be substantially enhanced by coupling to new heavy particles. A search for the decay Bs0→ μμ is performed bu using 2.4 fb-1 of integrated luminosity collected by ATLAS, and an upper limit on the branching fraction Br(Bs0→ μμ) is obtained.