Normalizing the recent LHCb measurement of ${\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_c\tau \overline{\nu }$ to the standard model (SM) prediction for the ${\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_c\mu \overline{\nu }$ rate, instead of a LEP measurement, provides a more consistent comparison with the SM prediction for the lepton flavor universality ratio $R({\mathrm{\Lambda }}_c)$. This modestly increases $R({\mathrm{\Lambda }}_c)$ compared to the quoted LHCb result, such that it no longer hints at a suppression compared to the SM, which would be hard to accommodate in new physics scenarios that enhance $R(D^{(*)})$. We point out that the fraction of excited states in inclusive semileptonic ${\mathrm{\Lambda }}_b$ decay may be significantly greater than the corresponding fraction in $B$ decays. Possible implications are speculated upon.

• Received 7 July 2022
• Accepted 21 December 2022

DOI:https://doi.org/10.1103/PhysRevD.107.L011502

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Published by the American Physical Society