The two-, three- and four-gluon sector of QCD in the Landau gauge

4th Symposium on Prospects in the Physics of Discrete Symmetries

Binosi, Daniele^1

European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT), Fondazione Bruno Kessler, Villa Tambosi, Strada delle Tabarelle 286, Villazzano (TN)

I-38123, Italy^1

关键词: Form factors;    Infrared divergences;    Landau gauge;    Nonperturbative;    Perturbative treatment;    Sharp contrast;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/631/1/012066/pdf
DOI  :  10.1088/1742-6596/631/1/012066

来源: IOP

【 摘 要 】

Due to the nonperturbative masslessness of the ghost field, ghost loops that contribute to gluon Green's functions in the Landau gauge display infrared divergences, akin to those one would encounter in a conventional perturbative treatment. This is in sharp contrast with gluon loops, in which the perturbative divergences are tamed by the dynamical generation of a gluon mass acting as an effective infrared cutoff. In this paper, after reviewing the full nonperturbative origin of this divergence in the two-gluon sector, we discuss its implications for the three- and four-gluon sector, showing in particular that some of the form factors characterizing the corresponding Green's functions are bound to diverge in the infrared.