Resummation approach in Fractional APT: How many loops do we need to calculate?
| dc.creator | Bakulev, Alexander P. | |
| dc.date | 2008-09-04 | |
| dc.date | 2008-10-22 | |
| dc.date.accessioned | 2026-07-07T10:11:57Z | |
| dc.date.available | 2026-07-07T10:11:57Z | |
| dc.description | We give a short introduction to the Analytic Perturbation Theory (APT) in QCD, discuss its problems and how they can be resolved in Fractional APT (FAPT), and give a brief report about taking into account heavy-quark thresholds in FAPT. Then we describe the resummation approach in the one-loop APT and FAPT, which produces finite answers in both Euclidean and Minkowski regions, provided the generating function P(t) of perturbative coefficients d_n is known. We consider its applications in estimations of the width of Higgs boson decay H^0\to b\bar{b} and of the Adler function D(Q^2) and the ratio R(s) in the N_f=4 region. In order to provide numerical answers we suggest very simple factorially growing models for perturbative coefficients d_n. We see that for the case of Higgs boson decay an accuracy of the order of 1% is reached at N^3LO approximation, when term d_3{\mathcal A}_3 is taken into account. In the case of Adler function D(Q^2) we have an accuracy of the order of 0.1% already at N^2LO (i. e., with taking into account d_2{\mathcal A}_2 term). The main conclusion is: In order to achieve an accuracy of the order of 1%, we do not need to calculate more than four loops and d_4 coefficients are needed only to estimate corresponding generating functions P(t). | |
| dc.description | 8 pages, 2 figures, invited talk at the International Workshop "Hadron Structure and QCD" (HSQCD'2008), Gatchina, Russia, June 30 - July 4, 2008. Reference bugs are fixed | |
| dc.identifier | https://arxiv.org/abs/0809.0761 | |
| dc.identifier | http://arxiv.org/abs/0809.0761 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/172027 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | Resummation approach in Fractional APT: How many loops do we need to calculate? | |
| dc.type | text |