Effective gluon mass and infrared fixed point in QCD

Autor: Aguilar, Arlene C., Papavassiliou, Joannis
Rok vydání: 2007
Předmět:
Zdroj: AIPConf.Proc.964:312-317,2007
Druh dokumentu: Working Paper
DOI: 10.1063/1.2823869
Popis: We report on a special type of solutions for the gluon propagator of pure QCD, obtained from the corresponding non-linear Schwinger-Dyson equation formulated in the Feynman gauge of the background field method. These solutions reach a finite value in the deep infrared and may be fitted using a massive propagator, with the crucial characteristic that the effective ``mass'' employed depends on the momentum transfer. Specifically, the gluon mass falls off as the inverse square of the momentum, as expected from the operator-product expansion. In addition, one may define a dimensionless quantity, which constitutes the generalization in a non-Abelian context of the universal QED effective charge. This strong effective charge displays asymptotic freedom in the ultraviolet whereas in the low-energy regime it freezes at a finite value, giving rise to an infrared fixed point for QCD.
Comment: 6 pages, 2 figures, Talk given at QCD@work 2007, Martina Franca, Italy, 16-20 June 2007
Databáze: arXiv
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