论文标题
研究CKM矩阵元素的比率$ | v_ {ub} |/| v_ {cb} | $来自半衰减的衰减$ b_s^0 \ 0 \ to k^-μ^+ν_μ$和kaon twist-twist-2分布幅度
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
论文作者
论文摘要
在本文中，我们根据半衰减$ b_s^0 \ to K^-μ^+ν_μ$计算Cabibbo-Kobayashi-Maskawa矩阵元素的比率，$ | v_ {ub} |/| v_ {cb} | $。它的关键组件，$ b_s \ to k $ transition formition $ f^{b_s \ to k} _+（q^2）$在QCD Light-Cone Sum Sum Rules方法中使用手性相关器进行了研究。 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.初始规模上的前四个矩$μ_0= 1〜 {\ rm gev} $是，$ \langleξ^1 \ rangle _ {2; k} = -0.0438^{+0.0053} _ {-0.0075} 0.010 $，$ \langleξ^3 \ rangle _ {2; k} = -0.0210^{+0.0024} _ { - 0.0035} $和$ \ langle配ξ^4 \ w^4 \ rangle _ {2; k} = 0.132 = 0.132 \ pm pm 0.006 $。他们对应的gegenbauer瞬间是，$ a^{2; k} _1 = -0.0731^{+0.0089} _ { - 0.0124} $，$ a^{2; k}; k} _2; -0.0114^{+0.0008} _ { - 0.0016} $和$ a^{2; k} _4 = 0.041^{ - 0.003} _ {+0.005} $。在大的后坐力区域，我们获得$ f^{b_s \ to k} _+（0）= 0.270^{+ 0.022} _ { - 0.030} $。通过将$ f^{b_s \至k} _+（q^2）$推送到所有物理允许的区域，我们获得了$ | v_ {ub} | $ - 独立的衰减宽度的neptonic decay $ b_s^0 \ 0 10^{ - 12} \ {\ rm gev} $，然后导致$ | v_ {ub} |/| v_ {cb} | = 0.072 \ PM0.005 $。
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 $|V_{ub}|/|V_{cb}| = 0.072\pm0.005$.
