标题： 淬火格点QCD中Kogut-Susskind夸克作用的π介子衰变常数 显示英文标题

标题： Pion decay constant for the Kogut-Susskind quark action in quenched lattice QCD

摘要： 我们研究了味数退耦的QCD晶格计算中π介子衰变常数$f_\pi$，重点在于重整化问题。数值模拟分别在耦合常数$\beta = 6.0$和6.2处进行，使用的晶格分别是$32^3\times 64$和$48^3\times 64$。通过规范不变和非规范不变的轴矢量流，用部分守恒轴矢量流的方法得到了所有Kogut-Susskind（KS）味的π介子衰变常数，并且重整化常数既通过非微扰方法也通过微扰论计算。我们在连续极限下得到最好的值为$f_\pi = 89(6)$MeV。通过对其他KS味的研究发现，用非微扰重整化常数得到的结果在连续极限下对于KS味来说是很好的收敛的，这证实了$\rm SU(4)_A$味对称性的恢复，而微扰重整化即使在连续极限下仍然表现出明显的味破缺效应。 显示英文摘要

摘要： We present a study for the pion decay constant $f_\pi$ in the quenched approximation to lattice QCD with the Kogut-Susskind (KS) quark action, with the emphasis given to the renormalization problems. Numerical simulations are carried out at the couplings $\beta = 6.0$ and 6.2 on $32^3\times 64$ and $48^3\times 64$ lattices, respectively. The pion decay constant is evaluated for all KS flavors via gauge invariant and non-invariant axial vector currents with the renormalization constants calculated by both non-perturbative method and perturbation theory. We obtain $f_\pi = 89(6)$ MeV in the continuum limit as the best value using the partially conserved axial vector current, which requires no renormalization. From a study for the other KS flavors we find that the results obtained with the non-perturbative renormalization constants are well convergent among the KS flavors in the continuum limit, confirming restoration of $\rm SU(4)_A$ flavor symmetry, while perturbative renormalization still leaves an apparent flavor breaking effect even in the continuum limit.