Observation of the Bs0 → D *± D ∓ decay

Abstract

A search for the B0 s → D∗±D∓ decay is performed using proton-proton collision data at centre-of-mass energies of 7, 8 and 13 TeV collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1 . The decay is observed with a high significance and its branching fraction relative to the B0 → D∗±D∓ decay is measured to be B(B0 s → D∗±D∓) B(B0 → D∗±D∓) = 0.137 ± 0.017 ± 0.002 ± 0.006 , where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the ratio of the B0 s and B0 hadronisation fractions.