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arXiv 0709.4368hep-lat
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具有重叠费米子的QCD:连续耦合和3-loop β函数

QCD with overlap fermions: Running coupling and the 3-loop beta-function

M. Constantinou, H. Panagopoulos

摘要:

本文用微扰理论计算了裸耦合常数g_0与MSbar重整化耦合g_MS之间的关系:g_0 = Z_g(g_0,a μ)g_MS ~ 2圈。对胶子采用标准Wilson作用量,对费米子采用重叠作用量。为了方便起见,我们使用了背景场技术,它只需要对手头的问题计算2点格林函数。我们的结果明确地依赖于费米子味数(N_f)和色数(N)。由于Z_g对重叠参数rho的依赖性不能解析地提取,因此我们将rho(0 < rho < 2)的允许范围内的不同值的结果制成表格,重点关注在模拟中最常用的值。Z_g的知识使我们能够导出裸β函数的3圈系数(beta_L(g_0)),它与1圈和2圈系数不同,是正则化相关的。对于N,N_f的不同选择,绘出了Z_g和beta_L(g_0)对ρ的非平凡依赖关系。

英文摘要:

We calculate the relation between the bare coupling constant g_0 and the MSbar-renormalized coupling g_MS: g_0 = Z_g(g_0,a μ) g_MS, to 2 loops in perturbation theory. We employ the standard Wilson action for gluons and the overlap action for fermions. For convenience, we have worked with the background field technique, which only requires evaluation of 2-point Green's function for the problem at hand. Our results depend explicitly on the number of fermion flavors (N_f) and colors (N). Since the dependence of Z_g on the overlap parameter rho cannot be extracted analytically, we tabulate our results for different values in the allowed range of rho (0 < rho < 2), focusing on values which are being used most frequently in simulations. Knowledge of Z_g allows us to derive the 3-loop coefficient of the bare beta-function (beta_L(g_0)) which, unlike the 1- and 2-loop coefficients, is regularization-dependent. The nontrivial dependence of Z_g and of beta_L(g_0) on rho is plotted for various choices of N, N_f.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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