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/ψπ+)/B(B+c→J/ψμ+νμ)=0.0469±0.0028(stat)±0.0046(syst), is at the lower end of available theoretical predictions.