Search for the rare decay D0 → μ+μ−

Abstract

A search for the rare decay D-0 -> mu(+) mu(-) is performed using a data sample, corresponding to an integrated luminosity of 0.9 fb(-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(D-0 -> mu(+) mu(-)) < 6.2 (7.6) x 10(-9) at 90% (95%) confidence level. This result represents an improvement of more than a factor twenty with respect to previous measurements.