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Title: On the interface between perturbative and nonperturbative QCD

The QCD running coupling αs(Q2) sets the strength of the interactions of quarks and gluons as a function of the momentum transfer Q . The Q2 dependence of the coupling is required to describe hadronic interactions at both large and short distances. In this article we adopt the light-front holographic approach to strongly-coupled QCD, a formalism which incorporates confinement, predicts the spectroscopy of hadrons composed of light quarks, and describes the low-Q2 analytic behavior of the strong coupling αs(Q2). The high-Q2 dependence of the coupling αs(Q2) is specified by perturbative QCD and its renormalization group equation. The matching of the high and low Q2 regimes of αs(Q2) then determines the scale Q0 which sets the interface between perturbative and nonperturbative hadron dynamics. The value of Q0 can be used to set the factorization scale for DGLAP evolution of hadronic structure functions and the ERBL evolution of distribution amplitudes. We discuss the scheme-dependence of the value of Q0 and the infrared fixed-point of the QCD coupling. Our analysis is carried out for the View the MathML source, g1, MOM and V renormalization schemes. Our results show that the discrepancies on the value of αs at large distance seen in the literaturemore » can be explained by different choices of renormalization schemes. We also provide the formulae to compute αs(Q2) over the entire range of space-like momentum transfer for the different renormalization schemes discussed in this article.« less
Authors:
ORCiD logo ; ;
Publication Date:
OSTI Identifier:
1236422
Report Number(s):
SLAC-PUB-16449
Journal ID: ISSN 0370-2693; arXiv:1601.06568
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics Letters. Section B; Journal Volume: 757; Journal Issue: C
Publisher:
Elsevier
Research Org:
SLAC National Accelerator Laboratory (SLAC)
Sponsoring Org:
US DOE Office of Science (DOE SC);High Energy Physics (HEP);JLAB-PHY-16-2198, DOE;OR;23177-3646
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS Phenomenology-HEP; HEPPH