Search for the rare decays Bs0→μ+μ− and B0→μ+μ−

A search for the decays Bs0→μ+μ− and B0→μ+μ− is performed with about 37pb−1 of pp collisions at s=7TeV collected by the LHCb experiment at the Large Hadron Collider at CERN. The observed numbers of events are consistent with the background expectations. The resulting upper limits on the branching ratios are B(Bs0→μ+μ−)<5.6×10−8 and B(B0→μ+μ−)<1.5×10−8 at 95% confidence level.