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

The branching fraction ratios of B[over ¯]^{0}→D^{+}τ^{-}ν[over ¯]{τ} and B[over ¯]^{0}→D^{*+}τ^{-}ν[over ¯]{τ} decays are measured with respect to their muonic counterparts, using a data sample corresponding to an integrated luminosity of 2.0 fb^{-1} collected by the LHCb experiment in proton-proton collisions at sqrt[s]=13 TeV. The reconstructed final states are formed by combining D^{+} mesons with τ^{-}→μ^{-}ν[over ¯]{μ}ν{τ} candidates, where the D^{+} is reconstructed via …