论文标题
电茶和中子衰减的晶格上的电动盒图
Electroweak box diagrams on the lattice for pion and neutron decay
论文作者
论文摘要
CKM矩阵在标准模型（SM）中构造是统一的。 CKM矩阵的第一行的最新分析显示了$ \ \ \3σ$张力，其unitarity。辐射校正的非扰动计算可以减少CKM基质元素中理论不确定性。在这里，我们使用七个$ n_f = 2+1+1 $ hisq-clover晶格计算了pion和kaon $β$衰减的electroweak盒子，并具有各种倾斜质量和晶格间距。连续性和手性限制是使用对$m_π$和$ a $的领先依赖性进行的，其中$m_π$外推被分别用于物理锥质量和$ su（3）$ su（3）$对称质量，分别用于锥子和kaon盒子的贡献。我们的结果是$ \ square_ {γw}^{va} |_π= 2.820（28）\ times 10^{ - 3} $和$ \ square_ {γw}^{va} | _ {k} = 2.384（17）\ times 10^{ - 3} $。
CKM matrix is unitary by construction in the standard model(SM). The recent analyses on the first row of CKM matrix show $ \approx 3σ$ tension with unitarity. Nonperturbative calculations of the radiative corrections can reduce the theory uncertainty in CKM matrix elements. Here we compute the electroweak box contribution to the pion and kaon $β$ decays using seven $N_f=2+1+1$ HISQ-Clover lattice with various pion mass and lattice spacing. The continuum and chiral limit is taken using the leading dependence on $M_π$ and $a$, where $M_π$ extrapolation is taken to the physical pion mass and $SU(3)$ symmetric mass for pion and kaon box contribution, respectively. Our results are $ \square_{γW}^{VA} |_π = 2.820 (28) \times 10^{-3} $ and $ \square_{γW}^{VA} |_{K} = 2.384 (17) \times 10^{-3} $.
