Measurement of the ratio of B+c branching fractions to J/ψπ+ and J/ψμ+νμ final states

Abstract

The first measurement that relates semileptonic and hadronic decay rates of the B + c meson is performed using proton-proton collision data corresponding to 1.0 fb − 1 of integrated luminosity collected with the LHCb detector. The measured value of the ratio of branching fractions, B ( B + c → J / ψ π + ) / B ( B + c → J / ψ μ + ν μ ) = 0.0469 ± 0.0028 ( stat ) ± 0.0046 ( syst ) , is at the lower end of available theoretical predictions.