Measurement of the Branching Fraction Ratios 𝑅⁡(𝐷+) and 𝑅⁡(𝐷*+) Using Muonic 𝜏 Decays

The branching fraction ratios of and decays are measured with respect to their muonic counterparts, using a data sample corresponding to an integrated luminosity of collected by the LHCb experiment in proton-proton collisions at . The reconstructed final states are formed by combining mesons with candidates, where the is reconstructed via the decay. The results are , 𝑅⁡(𝐷*+)=0.402±0.081±0.085, where the first uncertainties are statistical and the second systematic. The two measurements have a correlation coefficient of −0.39 and are compatible with the standard model.