Back to Search
Start Over
Interpreting LHCb's $\Lambda_b\to \Lambda_c\tau\bar\nu$ measurement and puzzles in semileptonic $\Lambda_b$ decays
- Publication Year :
- 2022
-
Abstract
- Normalizing the recent LHCb measurement of $\Lambda_b \to \Lambda_c \tau \bar\nu$ to the standard model (SM) prediction for the $\Lambda_b \to \Lambda_c \mu \bar\nu$ rate, instead of a LEP measurement, provides a more consistent comparison with the SM prediction for the lepton flavor universality ratio $R(\Lambda_c)$. This modestly increases $R(\Lambda_c)$ 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 $\Lambda_b$ decay may be significantly greater than the corresponding fraction in $B$ decays. Possible implications are speculated upon.<br />Comment: 3 pages
- Subjects :
- High Energy Physics - Phenomenology
Subjects
Details
- Database :
- arXiv
- Publication Type :
- Report
- Accession number :
- edsarx.2206.11282
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevD.107.L011502