|Vcb| determinations from B̅ → D(*) ℓ ν̅ decays within the SM and beyond
Abstract
We investigate the |Vcb| determinations from exclusive semi-leptonic B̅ → D(*)ℓν̅ decays, together with comprehensive Bayesian fit analyses of the B̅ → D(*) transition form-factors, by taking into account recent updates of experimental distribution data and theoretical evaluations. Several commonly adopted form-factor parameterizations, including BSZ, BGL and HQET, have been considered under different fit scenarios. We compare the fitted values and study how the |Vcb| determinations depend on the form-factor parameterizations and on the treatment of the experimental inputs. Following the fit setup adopted by the PDG, we find that the BSZ, BGL, and HQET results are mutually consistent at specific truncation orders of the form-factor parameterizations. Our representative determinations are |Vcb|=(39.3±0.3)×10−3 for BGL (NF=2) and (39.5±0.3)×10−3 for HQET (3/2/1), compatible with the official PDG average. We also consider new-physics effects that can contribute to B̅ → D(*)ℓν̅. The allowed regions remain compatible with vanishing new-physics Wilson coefficients at the 95% confidence level, and the improvements in agreement with the data are modest. The exclusive-inclusive |Vcb| puzzle remains unresolved in the present analysis.
Related
- Semileptonic B̅*c → (P, V) ℓ- ν̅ℓ decays within the self-consistent light-front quark model
- A Phenomenological Study of Semileptonic B+ and Bs0 Decays into Axial-Vector Mesons (D1(2420), D1′(2430), Ds1(2460), and Ds1′(2536)) within the Standard Model
- U-spin sum rules in charmed baryon decays beyond the U-spin limit
- Vector mesons leading-twist longitudinal distribution amplitudes and related semi-leptonic decays within QCD sum rules
- More than a Lifetime: Towards Precision Predictions for B-Meson Decays in the Standard Model and Beyond
BibTeX
@misc{fang2026determinations,
title = {{$|V_cb|$ determinations from $\barB \to D^(*) \ell \barν$ decays within the SM and beyond}},
author = {Wen-Sheng Fang and Syuhei Iguro and Xin-Qiang Li and Ria Sain and Ryoutaro Watanabe and Ben-Liang Zhang},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2606.17138},
eprint = {2606.17138},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.17138},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - |V_cb| determinations from B̅ → D^(*) ℓ ν̅ decays within the SM and beyond
AU - Wen-Sheng Fang
AU - Syuhei Iguro
AU - Xin-Qiang Li
AU - Ria Sain
AU - Ryoutaro Watanabe
AU - Ben-Liang Zhang
PY - 2026
DA - 2026/10/06
PB - arXiv
DO - 10.48550/arxiv.2606.17138
UR - https://arxiv.org/abs/2606.17138
AB - We investigate the |V_cb| determinations from exclusive semi-leptonic B̅ → D^(*)ℓν̅ decays, together with comprehensive Bayesian fit analyses of the B̅ → D^(*) transition form-factors, by taking into account recent updates of experimental distribution data and theoretical evaluations. Several commonly adopted form-factor parameterizations, including BSZ, BGL and HQET, have been considered under different fit scenarios. We compare the fitted values and study how the |V_cb| determinations depend on the form-factor parameterizations and on the treatment of the experimental inputs. Following the fit setup adopted by the PDG, we find that the BSZ, BGL, and HQET results are mutually consistent at specific truncation orders of the form-factor parameterizations. Our representative determinations are |V_cb|=(39.3±0.3)×10^−3 for BGL (N_F=2) and (39.5±0.3)×10^−3 for HQET (3/2/1), compatible with the official PDG average. We also consider new-physics effects that can contribute to B̅ → D^(*)ℓν̅. The allowed regions remain compatible with vanishing new-physics Wilson coefficients at the 95% confidence level, and the improvements in agreement with the data are modest. The exclusive-inclusive |V_cb| puzzle remains unresolved in the present analysis.
ER -