Test of lepton flavor universality by the measurement of the B0→D*-τ+ντ branching fraction using three-prong τ decays

The ratio of branching fractions R(D*-)≡B(B0→D*-τ+ντ)/B(B0→D*-μ+νμ) is measured using a data sample of proton-proton collisions collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb-1. The τ lepton is reconstructed with three ch