@Article{LHCbCollaborationAaij_etal2023, author="LHCb Collaboration (Aaij, R. et al and Jaimes Elles, S. J. and Jashal, B. K. and Martinez-Vidal, F. and Oyanguren, A. and Rebollo De Miguel, M. and Remon Alepuz, C. and Ruiz Vidal, J. and Sanderswood, I.", title="Measurement of the Ratios of Branching Fractions R(D*) and R(D0)", journal="Physical Review Letters", year="2023", publisher="Amer Physical Soc", volume="131", number="11", pages="111802--13pp", abstract="The ratios of branching fractions R(D*) = B((B) over bar -> D* tau(-) (v) over bar (tau))/B((B) over bar -> D*.mu(-)(v) over bar mu) and R(D-0) = B(B- -> D(0)t-mu(-)(v) over bar mu) are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb(-1) of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode tau(-) -> mu(-)v(tau)(v) over bar mu. The measured values are R(D) = 0.281 +/- 0.018 +/- 0.024 and R(D-0) = 0.441 +/- 0.060 +/- 0.066, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is rho = -0.43. The results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the standard model.", optnote="WOS:001158416000001", optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5943), last updated on Wed, 10 Apr 2024 12:45:16 +0000", issn="0031-9007", doi="10.1103/PhysRevLett.131.111802", opturl="https://arxiv.org/abs/2302.02886", opturl="https://doi.org/10.1103/PhysRevLett.131.111802", language="English" }