%0 Journal Article
%T Measurement of the Ratios of Branching Fractions R(D*) and R(D0)
%A LHCb Collaboration (Aaij, R. et al
%A Jaimes Elles, S. J.
%A Jashal, B. K.
%A Martinez-Vidal, F.
%A Oyanguren, A.
%A Rebollo De Miguel, M.
%A Remon Alepuz, C.
%A Ruiz Vidal, J.
%A Sanderswood, I.
%J Physical Review Letters
%D 2023
%V 131
%N 11
%I Amer Physical Soc
%@ 0031-9007
%G English
%F LHCbCollaborationAaij_etal2023
%O WOS:001158416000001
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5943), last updated on Wed, 10 Apr 2024 12:45:16 +0000
%X 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.
%R 10.1103/PhysRevLett.131.111802
%U https://arxiv.org/abs/2302.02886
%U https://doi.org/10.1103/PhysRevLett.131.111802
%P 111802-13pp