Study of K meson decay amplitudes from the lattice QCD

这个项目的目的是研究中性K介子系统中的Delta i=1/2规则，并通过对K介子衰变幅度的晶格计算，从粒子物理的标准模型计算CP破坏参数。我们考虑了K介子衰变到零动量两π介子的过程。我们的计算是在介子质量280 MeV下进行的。我们发现我们的方法对于计算衰变幅度Re(A0)和Re(A2)是有效的。我们的结果是Re(A0)/Re(A2)=24.7(14.7)，并显示了Delta i=1/2过程的增强。由此可望在未来用我们的方法在近物理点通过计算来理解Delta i=1/2规则。

An aim of this project is a study of the Delta I=1/2 rule in the neutral K meson system and a calculation of the CP violation parameter from the Standard model of the particle physics by a lattice calculation of the K meson decay amplitudes. We consider the K meson decay process to the zero momentum two pion. Our calculations are carried out at the pion mass 280 MeV. We found that our methods are efficient for a calculation of the decay amplitudes Re(A0) and Re(A2). Our result is Re(A0)/Re(A2)=24.7(14.7) and the enhancement of Delta I=1/2 process is shown. From this, understanding of the Delta I=1/2 rule by calculations with our method at near physical point is expected in the future.