Re+e and an effective QCD charge

Author(s)

Gomez, J. D. ^[1] ; Natale, A. A. ^{[1, 2]}

Affiliation

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210170 Santo Andre, SP - Brazil

^[2] Univ Estadual Paulista, Inst Fis Teor, Rua Dr Bento T Ferraz 271, Bloco 2, BR-01140070 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Physical Review D; v. 93, n. 1 JAN 25 2016.
• Web of Science Citations: 3

Abstract

We consider the electron-positron annihilation process into hadrons Re+e- up to O(alpha(3)(s)), and we adopt the smearing method suggest by Poggio, Quinn, and Weinberg to confront the experimental data with theory. As a theoretical model, we use a QCD coupling constant frozen in the low-energy regime, where this coupling can be parametrized in terms of an effective dynamical gluon mass (m(g)) which is determined through Schwinger-Dyson equations. In order to find the best fit between experimental data and theory, we perform a chi(2) study, that, within the uncertainties of the approach, has a minimum value when m(g)/A(QCD) is in the range 1.2-1.4. These values are in agreement with other phenomenological determinations of this ratio and lead to an infrared effective charge alpha(s)(0) approximate to 0.7. We comment how this effective charge may affect the global duality mass scale that indicates the frontier between perturbative and nonperturbative physics. (AU)

• FAPESP's process: 13/22079-8 - Physics of particles and fields: standard model and its extensions
• Grantee: Adriano Antonio Natale
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/24065-4 - Strong interaction phenomenology
• Grantee: John David Gomez Aguirre
• Support Opportunities: Scholarships in Brazil - Doctorate