Search for the rare decay D0→μ+μ−

A search for the rare decay D0→μ+μ− is performed using a data sample, corresponding to an integrated luminosity of 0.9fb−1, of pp collisions collected at a centre-of-mass energy of 7 TeV by the LHCb experiment. The observed number of events is consistent with the background expectations and corresponds to an upper limit of B(D0→μ+μ−)<6.2(7.6)×10−9 at 90% (95%) confidence level. This result represents an improvement of more than a factor twenty with respect to previous measurements.