Re+e and an effective QCD charge

Autor(es)

Gomez, J. D. ; Natale, A. A.

• Tipo de documento: Artigo Científico
• Fonte: PHYSICAL REVIEW D; v. 93, n. 1, p. 10-pg., 2016-01-25.

Resumo

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)

• Processo FAPESP: 13/24065-4 - Fenomenologia da interação forte
• Beneficiário: John David Gomez Aguirre
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/22079-8 - Física de partículas e campos: modelo padrão e suas extensões
• Beneficiário: Adriano Antonio Natale
• Modalidade de apoio: Auxílio à Pesquisa - Temático