发表机构
Centre for Theoretical Physics, Henan Normal University; Center for High Energy Physics, Henan Academy of Sciences; School of Physics and Electrical Engineering, Anyang Normal University（河南师范大学理论物理中心; 河南省科学院高能物理中心; 安阳师范学院物理与电气工程学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文在自洽光前夸克模型中研究$\bar{B}^*_c$介子的半轻子衰变，预言了分支比等可观测量，发现Cabibbo允许的衰变分支比达$10^{-6}$量级，有望在高亮度LHC上首次观测到。
AI 中文摘要
受ATLAS合作组最近观测到$B_c^*$介子及其在未来高亮度对撞机上有前景的发现潜力的启发，我们在标准模型框架内研究了半轻子衰变$\bar{B}^*_{c} \to (P, V) \ell^- \bar{\nu}_{\ell}$（其中$P=D$, $B_{d,s}$, $\eta_c(1S,\\,2S,\\,3S)$；$V=D^*$, $B^*_{d,s}$, $\psi(1S,\\,2S,\\,3S)$）。利用在自洽协变光前夸克模型中得到的相关形状因子，我们对若干物理可观测量给出了理论预言，包括分支比、分支比之比$R_{(L)}$、末态矢量介子的纵向极化分数、$\tau$轻子自旋不对称性和前后不对称性。研究发现，Cabibbo允许的$\bar{B}^*_{c}$ $\to$ $\bar{B}^*_{s} e^- \bar{\nu}_e$和$\bar{B}^*_{s} \mu^- \bar{\nu}_\mu$衰变的分支比达到${\cal O}(10^{-6})$量级，这可能在未来的高亮度大型强子对撞机上首先被观测到。
英文摘要
Motivated by the recent observation of the $B_c^*$ meson by the ATLAS Collaboration and its promising discovery potential at future high-luminosity colliders, we investigate the semileptonic decays $\bar{B}^*_{c} \to (P, V) \ell^- \barν_{\ell}$ ($P=D$, $B_{d,s}$, $η_c(1S,\,2S,\,3S)$; $V=D^*$, $B^*_{d,s}$, $ψ(1S,\,2S,\,3S)$) in the Standard Model. Using the relevant form factors obtained in the self-consistent covariant light-front quark model, we present theoretical predictions for several physical observables, including the branching fraction, the ratios of branching fractions $R_{(L)}$, the longitudinal polarization fraction of the daughter vector meson, the $τ$ lepton spin asymmetry and the forward-backward asymmetry. It is found that the branching fractions for the Cabibbo-favored $\bar{B}^*_{c}$ $\to$ $\bar{B}^*_{s} e^- \barν_e$ and $\bar{B}^*_{s} μ^- \barν_μ$ decays reach the order of ${\cal O}(10^{-6})$, which might be firstly observed at the future high-luminosity Large Hadron Collider.
CommentsAccepted for publication in Physical Review D. 41 pages, 5 figures, 6 tables
