arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新，休息一下吧，周末愉快~~
arXiv 2201.10820hep-ph
收藏

从半轻子衰变$B_s^0\to K^-μ^+ν_μ$和K介子扭转2分布振幅研究CKM矩阵元PDMATHAAB的比值

Investigating the ratio of CKM matrix elements $|V_{ub}|/|V_{cb}|$ from semileptonic decay $B_s^0\to K^-μ^+ν_μ$ and kaon twist-2 distribution amplitude

Tao Zhong, Hai-Bing Fu, Xing-Gang Wu

备注：
34 pages, 11 figures, comments welcome
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

本文基于半轻子衰变$B_s^0\to K^-μ^+ν_μ$计算了Cabibbo-Kobayashi-Maskawa矩阵元之比$|V_{ub}|/|V_{cb}|$。它的关键组成部分，$B_s\to K$跃迁形状因子$f^{B_s\to K}_+(q^2)$，在QCD光锥求和规则的方法，通过使用手征相关器进行了研究。导出的$f^{B_s\to K}_+(q^2)$主要由首旋部分控制，为了提高其精度，我们构造了一个新的K介子首旋分布振幅$ϕ_{2;K}(x,μ)$模型，其参数通过最小二乘法在背景场论中利用QCD求和规则计算得到.初始尺度$μ_0 = 1~{\rm GeV}$的前四个矩分别为$\langle ξ^1\rangle _{2;K} = -0.0438^{+0.0053}_{-0.0075}$、$\langle ξ^2\rangle _{2;K} = 0.262 \pm 0.010$、$\langle ξ^3\rangle _{2;K} = -0.0210^{+0.0024}_{-0.0035}$和$\langle ξ^4\rangle _{2;K} = 0.132 \pm 0.006$。它们对应的Gegenbauer矩分别为，$a^{2;K}_1 = -0.0731^{+0.0089}_{-0.0124}$，$a^{2;K}_2 = 0.182^{+0.029}_{-0.030}$，$a^{2;K}_3 = -0.0114^{+0.0008}_{-0.0016}$和$a^{2;K}_4 = 0.041^{-0.003}_{+0.005}$.在大反冲区，我们得到了$f^{B_s\to K} _+ (0) = 0.270^{+0.022}_{-0.030}$。通过将$f^{B_s\to K}_+(q^2)$外推到所有的物理允许区域，我们得到了半轻子衰变$B_s^0\to K^-μ^+ν_μ$的一个与$|V_{ub}|$无关的衰变宽度，$5.626^{+1.271}_{-0.864} \times 10^{-12}\ {\rm GeV}$，进而得到$|V_{ub}|/|V_{cb}| = 0.072\pm0.005$ .

英文摘要：

In this paper, we calculate the ratio of Cabibbo-Kobayashi-Maskawa matrix elements, $|V_{ub}|/|V_{cb}|$, based on the semileptonic decay $B_s^0\to K^-μ^+ν_μ$. Its key component, the $B_s\to K$ transition form factor $f^{B_s\to K}_+(q^2)$, is studied within the QCD light-cone sum rules approach by using a chiral correlator. The derived $f^{B_s\to K}_+(q^2)$ is dominated by the leading-twist part, and to improve its precision, we construct a new model for the kaon leading-twist distribution amplitude $ϕ_{2;K}(x,μ)$, whose parameters are fixed by using the least squares method with the help of the moments calculated by using the QCD sum rules within the background field theory. The first four moments at the initial scale $μ_0 = 1~{\rm GeV}$ are, $\langle ξ^1\rangle _{2;K} = -0.0438^{+0.0053}_{-0.0075}$, $\langle ξ^2\rangle _{2;K} = 0.262 \pm 0.010$, $\langle ξ^3\rangle _{2;K} = -0.0210^{+0.0024}_{-0.0035}$ and $\langle ξ^4\rangle _{2;K} = 0.132 \pm 0.006$, respectively. And their corresponding Gegenbauer moments are, $a^{2;K}_1 = -0.0731^{+0.0089}_{-0.0124}$, $a^{2;K}_2 = 0.182^{+0.029}_{-0.030}$, $a^{2;K}_3 = -0.0114^{+0.0008}_{-0.0016}$ and $a^{2;K}_4 = 0.041^{-0.003}_{+0.005}$, respectively. At the large recoil region, we obtain $f^{B_s\to K} _+ (0) = 0.270^{+0.022}_{-0.030}$. By extrapolating $f^{B_s\to K}_+(q^2)$ to all the physical allowable region, we obtain a $|V_{ub}|$-independent decay width for the semileptonic decay $B_s^0\to K^-μ^+ν_μ$, $5.626^{+1.271}_{-0.864} \times 10^{-12}\ {\rm GeV}$, which then leads to $|V_{ub}|/|V_{cb}| = 0.072\pm0.005$.

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。

↑