Strong constraints on the rare decays B(s)(0) → μ+ μ- and B0 → μ+ μ-

Phys Rev Lett. 2012 Jun 8;108(23):231801. doi: 10.1103/PhysRevLett.108.231801. Epub 2012 Jun 5.

Abstract

A search for B(s)(0) → μ+ μ- and B0 → μ+ μ decays is performed using 1.0 fb(-1) of pp collision data collected at sqrt[s] = 7 TeV with the LHCb experiment at the Large Hadron Collider. For both decays, the number of observed events is consistent with expectation from background and standard model signal predictions. Upper limits on the branching fractions are determined to be B(B(s)(0) → μ+ μ-) < 4.5(3.8)×10(-9) and B(B0 → μ+ μ-) < 1.0(0.81)×10(-9) at 95% (90%) confidence level.