TY  - JOUR
AU  - LHCb Collaboration (Aaij, R. et al
AU  - Jaimes Elles, S. J.
AU  - Jashal, B. K.
AU  - Martinez-Vidal, F.
AU  - Oyanguren, A.
AU  - Rebollo De Miguel, M.
AU  - Remon Alepuz, C.
AU  - Ruiz Vidal, J.
AU  - Sanderswood, I.
PY  - 2023
DA  - 2023//
TI  - Measurement of the Ratios of Branching Fractions R(D*) and R(D0)
T2  - Phys. Rev. Lett.
JO  - Physical Review Letters
SP  - 111802
EP  - 13pp
VL  - 131
IS  - 11
PB  - Amer Physical Soc
AB  - 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.
SN  - 0031-9007
UR  - https://arxiv.org/abs/2302.02886
UR  - https://doi.org/10.1103/PhysRevLett.131.111802
DO  - 10.1103/PhysRevLett.131.111802
LA  - English
N1  - WOS:001158416000001
ID  - LHCbCollaborationAaij_etal2023
ER  -