@article{022d97c0a5dd497ab0483dba6adb8f4c,

title = "Measurement of the Ratios of Branching Fractions R (D∗) and R (D0)",

abstract = "The ratios of branching fractions R(D∗)B(B¯→D∗τ-ν¯τ)/B(B¯→D∗μ-ν¯μ) and R(D0)B(B-→D0τ-ν¯τ)/B(B-→D0μ-ν¯μ) 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 τ-→μ-ντν¯μ. The measured values are R(D∗)=0.281±0.018±0.024 and R(D0)=0.441±0.060±0.066, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is ρ=-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.",

author = "{LHCb Collaboration} and R. Aaij and Abdelmotteleb, {A. S.W.} and {Abellan Beteta}, C. and F. Abudin{\'e}n and T. Ackernley and B. Adeva and M. Adinolfi and P. Adlarson and H. Afsharnia and C. Agapopoulou and Aidala, {C. A.} and Z. Ajaltouni and S. Akar and K. Akiba and P. Albicocco and J. Albrecht and F. Alessio and M. Alexander and {Alfonso Albero}, A. and Z. Aliouche and {Alvarez Cartelle}, P. and R. Amalric and S. Amato and Amey, {J. L.} and Y. Amhis and L. An and L. Anderlini and M. Andersson and A. Andreianov and M. Andreotti and D. Andreou and D. Ao and F. Archilli and A. Artamonov and M. Artuso and E. Aslanides and M. Atzeni and B. Audurier and {Bachiller Perea}, {I. B.} and S. Bachmann and M. Bachmayer and Back, {J. J.} and A. Bailly-Reyre and {Baladron Rodriguez}, P. and V. Balagura and W. Baldini and S. Blusk and Rudolph, {M. S.} and {Silva Coutinho}, R. and T. Skwarnicki",

note = "Publisher Copyright: {\textcopyright} 2023 CERN.",

year = "2023",

month = sep,

day = "15",

doi = "10.1103/PhysRevLett.131.111802",

language = "English (US)",

volume = "131",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

number = "11",

}