arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2007.06587hep-phhep-exhep-lat
收藏

标量模型中$b\rightarrow cτν$衰变模之间的关系

Relations between $b\rightarrow cτν$ Decay Modes in Scalar Models

Stefan Schacht, Amarjit Soni

摘要:

作为强子矩阵元的Ward恒等式的结果,我们发现半轻子衰变模的微分衰变率与夸克能级跃迁$b\rightarrow cτν$之间的关系,这在标量模型中是有效的。衰减模式相关的标量形状因子是唯一必要的理论成分的关系。否则,他们将可测量的衰变率作为轻子对$q^2$的不变质量平方的函数,以这样一种方式找到一个通用的衰变模式独立函数,分别用于矢量和赝标介子的衰变。这可以应用于衰变$B\rightarrow D^{*}τν$、$B_s\rightarrow D_s^*τν$、$B_c\rightarrow J/ψτν$和$B\rightarrow Dτν$、$B_s\rightarrow D_sτν$、$B_c\rightarrow η_cτν$,并对$R(D^{(*)})$、$R(D_s^{(*)})$、$R(J/ψ)$、$R(η_c)$和$\mathcal{B}(B_c\rightarrow τν)$产生影响。特征$q^2$依赖性的斜率和曲率与标量新物理参数成比例,促进它们的直接提取,与全局拟合互补。

英文摘要:

As a consequence of the Ward identity for hadronic matrix elements, we find relations between the differential decay rates of semileptonic decay modes with the underlying quark-level transition $b\rightarrow cτν$, which are valid in scalar models. The decay-mode dependent scalar form factor is the only necessary theoretical ingredient for the relations. Otherwise, they combine measurable decay rates as a function of the invariant mass-squared of the lepton pair $q^2$ in such a way that a universal decay-mode independent function is found for decays to vector and pseudoscalar mesons, respectively. This can be applied to the decays $B\rightarrow D^{*}τν$, $B_s\rightarrow D_s^*τν$, $B_c\rightarrow J/ψτν$ and $B\rightarrow Dτν$, $B_s\rightarrow D_sτν$, $B_c\rightarrow η_cτν$, with implications for $R(D^{(*)})$, $R(D_s^{(*)})$, $R(J/ψ)$, $R(η_c)$, and $\mathcal{B}(B_c\rightarrow τν)$. The slope and curvature of the characteristic $q^2$-dependence is proportional to scalar new physics parameters, facilitating their straight forward extraction, complementary to global fits.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑