Study of non-perturbative effects of gauge theories using numerical methods

Suzuki等人在SU（2）胶子动力学中用规范无关的方法观察到了色禁闭的阿贝尔机制。采用了一种新的降噪方法，即随机规范变换和多能级方法。从阿贝尔波利亚科夫回路相关器推导出的静态势为我们提供了正确的弦张力。此外，只有阿贝尔Polyakov环中的第二部分负责弦张力。定义在任意色方向上的阿贝尔电场被压缩，相应的超磁流起着磁超电流的作用。的渗透和相干长度与以前观察到的阿贝尔投影后一致。由于所有色通道中的阿贝尔中性态仅限于色单态，SU（2）胶子动力学中的非阿贝尔色禁闭可以理解为单极子引起的阿贝尔对偶Meissner效应。久保发现，基于非阿贝尔离散群的某种味对称性可以在低能量下实现。离散味对称性可以起源于紧化额外维的几何。他们的预测可以通过未来的实验，如大型强子Colider实验和超级B-工厂实验在KEK.The运行耦合和Kugo-Ojima约束参数进行了分析Nakajima和他的colaborator在格点朗道规范QCD使用淬火和非淬火规范配置。虽然鬼和胶子敷料功能测量的运行耦合红外抑制，运行耦合有一个最大值$\alpha_0\sim 2-2.5$在约$q=0.5$ GeV的费米子作用（威尔逊费米子和Kogut-Susskind费米子）。在淬火模拟中饱和到约0.8的Kugo-Ojima参数$c$与使用Asqtad作用产生的MILC配置中的预期值1一致。

Abelian mechanism of color confinement is observed bu Suzuki et al. in a gauge-independent way in SU (2) gluodynamics. A new noise-reduction method using random gauge transformations as well as the multi-level method are adopted. A static potential derived from Abelian Polyakov loop correlators gives us the correct string tension. Moreover only the monopole part in the Abelian Polyakov loop is responsible for the string tension. Abelian electric fields defined in an arbitrary color direction are squeezed and the corresponding monopole currents play the role of magnetic super currents. The penetration and the coherence lengths are consistent with those observed previously after Abelian projections. Since an Abelian neutral state in all color channels is restricted to a color-singlet state alone, the non-Abelian color confinement in SU (2) gluodynamics can be understood as the Abelian dual Meissner effect due to monopoles.Kubo found that a certain flavor symmetry based on a non-abelian discrete group can be realized at low energies. Discrete flavor symmetries can originate from the geometry of compactified extra dimensions. They make predictions that can be tested by future experiments such as Large Hadron Colider experiments and Super B-Factory experiments at KEK.The running coupling and the Kugo-Ojima confinement parameter were analyzed by Nakajima and his colaborator in lattice Landau gauge QCD with use of quenched and unquenched gauge configurations. Although the running coupling measured by the ghost and gluon dressing function is infrared suppressed, the running coupling has a maximum of $\alpha_0\sim 2-2.5$ at around $q=0.5$ GeV irrespective of the fermion actions (Wilson fermions and Kogut-Susskind fermions). The Kugo-Ojima Parameter $c$ which saturates to about 0.8 in quenched simulations becomes consistent with the expected value, 1, in the MILC configurations produced with the use of Asqtad action.