Impact of $\Lambda_b\to \Lambda_c\tau\nu$ measurement on New Physics in $b\to c \, l \nu$ transitions
| Title: | Impact of $\Lambda_b\to \Lambda_c\tau\nu$ measurement on New Physics in $b\to c \, l \nu$ transitions |
|---|---|
| Authors: | Fedele, Marco, Blanke, Monika, Crivellin, Andreas, Iguro, Syuhei, Kitahara, Teppei, Nierste, Ulrich, Watanabe, Ryoutaro |
| Source: | Phys. Rev. D 107 (2023) 055005 |
| Publication Year: | 2022 |
| Collection: | High Energy Physics - Experiment High Energy Physics - Phenomenology |
| Subject Terms: | High Energy Physics - Phenomenology, High Energy Physics - Experiment |
| More Details: | Measurements of the branching ratios of $B \to D^{(*)}\tau\bar\nu/B \to D^{(*)}\ell\bar\nu$ and $B_c\to J/\psi\, \tau\bar\nu/B_c\to J/\psi\, \ell\bar\nu$ by the BaBar, Belle and LHCb collaborations consistently point towards an abundance of taus compared to channels with light leptons. However, the ratio $\Lambda_b \to\Lambda_c \tau\bar\nu/\Lambda_b \to\Lambda_c \ell\bar\nu$ shows a relative deficit in taus. In this paper, we critically address whether data still points towards a coherent pattern of deviations, in particular in light of the sum rule relating these decays in a model-independent way. We find that no common new physics explanation of all ratios is possible (within $2\sigma$ or $1.5\sigma$, depending on the ${\cal R}(\Lambda_c)$ normalization to light lepton channels). While this inconsistency could be a statistical fluctuation, further measurements are required in order to converge to a coherent pattern of experimental results. Comment: 12 pages, 3 tables. Minor corrections, conclusions unchanged, matches journal version |
| Document Type: | Working Paper |
| DOI: | 10.1103/PhysRevD.107.055005 |
| Access URL: | http://arxiv.org/abs/2211.14172 |
| Accession Number: | edsarx.2211.14172 |
| Database: | arXiv |
| DOI: | 10.1103/PhysRevD.107.055005 |
|---|