Publication
Title
Instanton contribution to the quark form factor
Author
Abstract
The nonperturbative effects in the quark form factor are considered in the Wilson loop formalism. The properties of the Wilson loops with cusp singularities are studied taking into account the perturbative and nonperturbative contributions, where the latter are considered within the framework of the instanton liquid model. For the integration path corresponding to this form factor-the angle with infinite sides-the explicit expression for the vacuum expectation value of the Wilson operator is found to leading order. The calculations are performed in the weak-field limit for the instanton vacuum contribution and compared with the one- and two-loop order results for the perturbative part. It is shown that the instantons produce the powerlike corrections to the perturbative result, which are comparable in magnitude with the perturbative part at the scale of order of the inverse average instanton size. It is demonstrated that the instanton contributions to the quark form factor are exponentiated to high orders in the small instanton density parameter.
Language
English
Source (journal)
Physical review : D : particles and fields. - Lancaster, Pa, 1970 - 2003
Publication
Lancaster, Pa : 2002
ISSN
0556-2821
Volume/pages
66:7(2002), 9 p.
Article Reference
074009
ISI
000179068200021
Medium
E-only publicatie
Full text (Publisher's DOI)
Full text (open access)
UAntwerpen
Faculty/Department
[E?say:metaLocaldata.cgzprojectinf]
Publication type
Subject
External links
Web of Science
Record
Identification
Creation 06.01.2015
Last edited 08.11.2017