论文标题
Landau量规QCD和QCD样理论的复杂极点和光谱函数
Complex poles and spectral functions of Landau gauge QCD and QCD-like theories
论文作者
论文摘要
鉴于人们期望复杂的杆的存在是限制的信号，我们研究了landau量规QCD QCD和QCD类似于类似Yang-Mills理论的Gluon质量术语的有效模型的Gluon，Quark和Ghost Expagors的分析结构，我们称之为大型的Yang-Mills模型。在此模型中，我们特别研究了模型的参数空间中的复杂极数的数量，该参数空间由量规耦合常数，gluon质量和夸克质量$ su（3）$（3）$（3）$以及各种数量的夸克风味$ n_f $在渐近自由区域内。 $ n_f = 2 $ QCD的最佳拟合参数的Gluon和Quark繁殖器都有一对复杂的共轭电线杆，而Gluon传播器中的复杂杆的数量在零和四之间变化，这取决于夸克口味和夸克质量的数量。此外，作为一般特征，我们认为该模型具有非零夸克质量的GLUON光谱函数在红外极限中为负。与胶子形成鲜明对比的是，夸克和幽灵传播器对本文采用的当前近似值中的夸克风味数量不敏感。这些结果表明，限制机制的细节可能取决于夸克口味和夸克质量的数量。
In view of the expectation that the existence of complex poles is a signal of confinement, we investigate the analytic structure of the gluon, quark, and ghost propagators in the Landau gauge QCD and QCD-like theories by employing an effective model with a gluon mass term of the Yang-Mills theory, which we call the massive Yang-Mills model. In this model, we particularly investigate the number of complex poles in the parameter space of the model consisting of gauge coupling constant, gluon mass, and quark mass for the gauge group $SU(3)$ and various numbers of quark flavors $N_F$ within the asymptotic free region. Both the gluon and quark propagators at the best-fit parameters for $N_F=2$ QCD have one pair of complex conjugate poles, while the number of complex poles in the gluon propagator varies between zero and four depending on the number of quark flavors and quark mass. Moreover, as a general feature, we argue that the gluon spectral function of this model with nonzero quark mass is negative in the infrared limit. In sharp contrast to gluons, the quark and ghost propagators are insensitive to the number of quark flavors within the current approximations adopted in this paper. These results suggest that details of the confinement mechanism may depend on the number of quark flavors and quark mass.
