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Reconciling the contour-improved and fixed-order approaches for tau hadronic spectral moments. Part I. Renormalon-free gluon condensate scheme

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Autor(es):
Benitez-Rathgeb, Miguel A. ; Boito, Diogo ; Hoang, Andre H. ; Jamin, Matthias
Número total de Autores: 4
Tipo de documento: Artigo Científico
Fonte: Journal of High Energy Physics; v. N/A, n. 7, p. 50-pg., 2022-07-04.
Resumo

We propose a simple and easy-to-implement scheme for a renormalon-free gluon condensate (GC) matrix element, which is analogous to implementations of short-distance heavy-quark mass renormalization schemes existing in the literature already for a long time. Because the scheme is based on a perturbative subtraction at the level of the matrix element, with a freely adaptable infrared factorization scale, it can be implemented with little effort for any observable where the GC is relevant. The scheme depends on the renormalon norm of the GC which has to be supplemented independently. We apply the scheme to the fixed-order (FOPT) and contour-improved (CIPT) perturbative expansions of tau hadronic spectral function moments. These expansions exhibit a long-standing discrepancy for moments used in high-precision determinations of the strong coupling in the commonly used GC scheme that is not renormalon-free. We show that the scheme is capable of resolving the FOPT-CIPT discrepancy problem. At the same time, the perturbative behaviour of the moments that previously showed bad convergence properties and for which the non-perturbative corrections from the GC are sizeable, is substantially improved. The new GC scheme may provide a powerful theoretical tool for future phenomenological applications. (AU)

Processo FAPESP: 21/06756-6 - Testes do modelo padrão: QCD de precisão e g-2 do múon
Beneficiário:Diogo Rodrigues Boito
Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores - Fase 2