Perturbative expansion of the QCD Adler function improved by renormalization-group summation and analytic continuation in the Borel plane

0432818 - FZÚ 2015 RIV US eng J - Článek v odborném periodiku
Abbas, G. - Ananthanarayan, B. - Caprini, I. - Fischer, Jan
Perturbative expansion of the QCD Adler function improved by renormalization-group summation and analytic continuation in the Borel plane.
Physical Review D: Particles, Fields, Gravitation and Cosmology. Roč. 87, č. 1 (2013), "014008-1"-"014008-14". ISSN 1550-7998
Grant CEP: GA MŠMT(CZ) LG13031
Institucionální podpora: RVO:68378271
Klíčová slova: perturbative expansion * Borel transformation * Adler function
Kód oboru RIV: BE - Teoretická fyzika
Impakt faktor: 4.864, rok: 2013

We examine the large-order behavior of a recently proposed renormalization-group-improved expansion of the Adler function in perturbative QCD, which sums in an analytically closed form the leading logarithms accessible from renormalization-group invariance. The expansion is first written as an effective series in powers of the one-loop coupling, and its leading singularities in the Borel plane are shown to be identical to those of the standard "contour-improved'' expansion. Applying the technique of conformal mappings for the analytic continuation in the Borel plane, we define a class of improved expansions, which implement both the renormalization-group invariance and the knowledge about the large-order behavior of the series. Detailed numerical studies of specific models for the Adler function indicate that the new expansions have remarkable convergence properties up to high orders.
Trvalý link: http://hdl.handle.net/11104/0237181