skip to main content

Title: Variational perturbation theory and nonperturbative calculations in QCD

A nonperturbative approach based on the variational perturbation theory in quantum chromodynamics is developed. The variational series is different from the conventional perturbative expansion and can be used to go beyond the weak-coupling regime. The approach suggested takes into account the summation of threshold singularities and the involvement of nonperturbative light quark masses. Phenomenological applications of this approach to describe physical quantities connected with the hadronic {tau}-decay data: the R{sub {tau}} ratio, the light-quark Adler function, and the smeared R{sub {Delta}} function are presented. The description of examined quantities includes an infrared region and, therefore, they cannot be directly calculated within the standard perturbation theory. It is shown that in spite of this fact the approach suggested gives a rather good result for these quantities down to the lowest energy scale.
Authors:
 [1]
  1. Joint Institute for Nuclear Research (Russian Federation)
Publication Date:
OSTI Identifier:
22212654
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Atomic Nuclei; Journal Volume: 76; Journal Issue: 10; Other Information: Copyright (c) 2013 Pleiades Publishing, Ltd.; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; COUPLING; D QUARKS; DECAY; EXPANSION; HADRONS; MASS; PERTURBATION THEORY; QUANTUM CHROMODYNAMICS; SINGULARITY; U QUARKS; VARIATIONAL METHODS