Observation of B[0s χc1φ decay and study of: B0 -> χ c1,2K*1 decays

The first observation of the decay B0s → χc1φ and a study of B0 → χc1,2K*0 decays are presented. The analysis is performed using a dataset, corresponding to an integrated luminosity of 1.0 fb-1, collected by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. The following ratios of branching fractions are measured: Where the third uncertainty is due to the limited knowledge of the branching fractions of χc → J/ψγ modes. © 2013 CERN. Published by Elsevier B.V

Search for the rare decay D0→μ+μ−D^0 \to \mu^+ \mu^-

22 pages, 8 figures, Submitted to Physics Letters BA search for the rare decay $D^0 \to \mu^+ \mu^-$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 \mbox{${\cal B}(D^0 \to \mu^+ \mu^-) < 6.2(7.6) \times 10^{-9}$} at \mbox{90%} \mbox{(95%)} confidence level. This result represents an improvement of more than a factor twenty with respect to previous measurements