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arXiv 2212.10089hep-phhep-th
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红外小参数QCD:π介子衰变常数

Small parameters in infrared QCD: The pion decay constant

Marcela Peláez, Urko Reinosa, Julien Serreau, Nicolás Wschebor

摘要:

我们继续我们的调查QCD动力学的Curci-Ferrari有效拉格朗日,变形的Faddeev-Popov一个朗道规范与树级胶子质量项。在以前的工作中,我们已经研究了手征对称性破缺的夸克传播子的水平上的动力学,特别是,一个组成夸克质量的动力学产生。在本文中,我们研究了相关的戈德斯通模式,π介子,我们计算的π介子衰变常数的手征极限。我们的方法利用了这样一个事实,即耦合(定义在泰勒计划)在纯规范部门是微扰的,在晶格模拟中观察到的,连同$1/N_c$ -扩展,允许一个系统的,可控的近似方案在低能量区的QCD。在领先的顺序,这导致了著名的彩虹阶梯重申。我们研究的区域参数空间的模型,给出物理值的π衰变常数。这使得人们可以使用物理测量的量来约束胶子质量参数作为耦合的函数。

英文摘要:

We continue our investigation of the QCD dynamics in terms of the Curci-Ferrari effective Lagrangian, a deformation of the Faddeev-Popov one in the Landau gauge with a tree-level gluon mass term. In a previous work we have studied the dynamics of chiral symmetry breaking at the level of the quark propagator and, in particular, the dynamical generation of a constituent quark mass. In the present article, we study the associated Goldstone mode, the pion, and we compute the pion decay constant in the chiral limit. Our approach exploits the fact that the coupling (defined in the Taylor scheme) in the pure gauge sector is perturbative, as observed in lattice simulations which, together with a $1/N_c$-expansion, allows for a systematic, controllable approximation scheme in the low energy regime of QCD. At leading order, this leads to the well-known rainbow-ladder resummation. We study the region of parameter space of the model that gives physical values of the pion decay constant. This allows one to constrain the gluon mass parameter as a function of the coupling using a physically measured quantity.

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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