K_l3 form factors at the physical point: Toward the continuum limit
K_l3 form factors at the physical point: Toward the continuum limit
复制标题
物理点处的 K_l3 形状因数：走向连续极限
DOI：
10.1103/physrevd.106.094501
复制
发表时间：
2022
影响因子：
5
通讯作者：
PACS Collaboration
中科院分区：
文献类型：
--
作者：
Ishikawa Ken-ichi;Ishizuka Naruhito;Kuramashi Yoshinobu;Namekawa Yusuke;Taniguchi Yusuke;Ukita Naoya;Yamazaki Takeshi;Yoshie Tomoteru;PACS Collaboration
本文用非微扰改进的Wilson夸克作用量和Iwasaki规范作用量计算了K介子半轻子衰变过程的形状因子。除了我们先前在晶格间距处的计算之外，我们在第二晶格间距0.063 fm处执行计算。利用在两种晶格间距下的局部矢量流和守恒矢量流的三点函数的形状因子的结果，同时进行动量传递的连续外推和插值，得到连续极限下动量传递为零时的形状因子值.通过对几种拟合形式和不同数据的稳定性研究，得到了分别由拟合形式的选择和同位旋破缺效应引起的系统误差，其中第一、第二和第三误差为统计误差。此外，我们还得到了形状因子的斜率和曲率，以及由形状因子的动量传递依赖关系得到的相空间积分。结合衰变的实验输入和我们的值，确定了一个Cabibbo-Kobayashi-Maskawa矩阵元，它的误差包含了实验误差和格点计算误差。这个值与最近的格点QCD结果以及通过K介子轻子衰变过程确定的值是一致的。我们观察到我们的值和从CKM矩阵的酉性贬值之间的一些紧张关系，而它取决于误差的大小。我们还发现，用六个衰变过程的相空间积分所确定的结果与上述结果是一致的。
We present updated results for the form factors of the kaon semileptonicdecay process calculated withnonperturbatively-improved Wilson quark action and Iwasaki gauge action at the physical point on large volumes of more than. In addition to our previous calculation at the lattice spacing, we perform a calculation at the second lattice spacing of 0.063 fm. Using the results for the form factors extracted from 3-point functions with the local and also conserved vector currents at the two lattice spacings, continuum extrapolation and interpolation of the momentum transfer are carried out simultaneously to obtain the value of the form factorat the zero momentum transfer in the continuum limit. After investigation of stability ofagainst several fit forms and different data, we obtain, where the first, second, and third errors are statistical, systematic errors from choice of the fit forms and isospin breaking effect, respectively. Furthermore, we obtain the slope and curvature of the form factors, and the phase space integral from the momentum transfer dependence of the form factors. Combining our value ofand experimental input of thedecay, one of the Cabibbo-Kobayashi-Maskawa matrix elementsis determined as, whose error contains the experimental one as well as that in the lattice calculation. This value is reasonably consistent with the ones determined from recent lattice QCD results ofand also the one determined through the kaon leptonic decay process. We observe some tension between our value andevaluated from the unitarity of the CKM matrix with, while it depends on the size of the error of. It is also found thatdetermined with our phase space integrals through sixdecay processes is consistent with the above one using.