Wednesday 4 September 2013 

Speaker: Marc-Olivier Bettler (Cambridge University)


Title: "Recent results on the B->\mu\mu branching fractions" 

Abstract: The rare decays of Bd->mu+mu- and Bs->mu+mu- are highly 
suppressed in the Standard Model and very sensitive to physics beyond 
the Standard Model. This summer, the CMS and LHCb collaborations 
announced measurements of the rare Bs->mu+mu- decay branching fraction 
consistent with the SM. Each experiment saw this decay with significance 
in excess of four standard deviations. Limits have also been set on the 
Bd->mu+mu- decay. Limits on the Bd mode have been set. The LHCb analysis 
will be presented, as well as a preliminary combination of the decay 
branching fraction measurement, with a combined significance in excess 
of five standard deviations.