A search for rare B → Dµ+µ − decays

Abstract

Abstract: A search for rare B → Dµ+µ − decays is performed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1 . No signifcant signals are observed in the non-resonant µ +µ − modes, and upper limits of B B0 → D 0 µ +µ − < 5.1 × 10−8 , B meson with a c and u quark respectively in proton-proton collisions. Each result is either the frst such measurement or an improvement by three orders of magnitude on an existing limit. Separate upper limits are calculated when the muon pair originates from a J/ψ → µ +µ − decay. The branching fraction of B+ c → D+ s J/ψ multiplied by the fragmentation-fraction ratio is measured to be fc fu · B B + c → D+ s J/ψ = (1.63 ± 0.15 ± 0.13) × 10−5 , where the frst uncertainty is statistical and the second systematic.