Measurement of the Ratios of Branching Fractions R(D^{*}) and R(D^{0}).



Aaij, R, Abdelmotteleb, ASW, Abellan Beteta, C, Abudinén, F, Ackernley, T ORCID: 0000-0002-5951-3498, Adeva, B, Adinolfi, M, Adlarson, P, Afsharnia, H, Agapopoulou, C
et al (show 1056 more authors) (2023) Measurement of the Ratios of Branching Fractions R(D^{*}) and R(D^{0}). Physical review letters, 131 (11). 111802-.

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Abstract

The ratios of branching fractions R(D^{*})≡B(B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]→D^{*}μ^{-}ν[over ¯]_{μ}) and R(D^{0})≡B(B^{-}→D^{0}τ^{-}ν[over ¯]_{τ})/B(B^{-}→D^{0}μ^{-}ν[over ¯]_{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^{-}ν_{τ}ν[over ¯]_{μ}. 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 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.

Item Type: Article
Uncontrolled Keywords: LHCb Collaboration
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 30 Nov 2023 12:37
Last Modified: 30 Nov 2023 12:37
DOI: 10.1103/physrevlett.131.111802
Open Access URL: https://journals.aps.org/prl/pdf/10.1103/PhysRevLe...
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3177087