Massive analytic invariant charge in QCD

Journal Article · Sat Jan 01 04:00:00 EST 2005 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.71.016009· OSTI ID:20705765

Nesterenko, A V ^[1]; Papavassiliou, J ^[1]

---

1. Departamento de Fisica Teorica and IFIC, Centro Mixto, Universidad de Valencia-CSIC, E-46100, Burjassot, Valencia (Spain)

The low-energy behavior of a recently proposed model for the massive analytic running coupling of QCD is studied. This running coupling has no unphysical singularities, and in the absence of masses displays infrared enhancement. The inclusion of the effects due to the mass of the lightest hadron is accomplished by employing the dispersion relation for the Adler D function. The presence of the nonvanishing pion mass tames the aforementioned enhancement, giving rise to a finite value for the running coupling at the origin. In addition, the effective charge acquires a plateaulike behavior in the low-energy region of the timelike domain. This plateau is found to be in agreement with a number of phenomenological models for the strong running coupling. The developed invariant charge is applied in the processing of experimental data on the inclusive {tau} lepton decay. The effects due to the pion mass play an essential role here as well, affecting the value of the QCD scale parameter {lambda} extracted from these data. Finally, the massive analytic running coupling is compared with the effective coupling arising from the study of Schwinger-Dyson equations, whose infrared finiteness is due to a dynamically generated gluon mass. A qualitative picture of the possible impact of the former coupling on the chiral symmetry breaking is presented.

• OSTI ID: 20705765
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 1 Vol. 71; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHIRAL SYMMETRY
COUPLING
DISPERSION RELATIONS
EFFECTIVE CHARGE
GLUONS
PARTICLE DECAY
PIONS
QUANTUM CHROMODYNAMICS
REST MASS
SCHWINGER FUNCTIONAL EQUATIONS
SCHWINGER SOURCE THEORY
SINGULARITY
SYMMETRY BREAKING
TAU PARTICLES