QCD WITH LARGE NUMBER OF QUARKS - EFFECTS OF THE INSTANTON-ANTI-INSTANTON PAIRS

Authors
VELKOVSKY M SHURYAK E
Citation
M. Velkovsky et E. Shuryak, QCD WITH LARGE NUMBER OF QUARKS - EFFECTS OF THE INSTANTON-ANTI-INSTANTON PAIRS, Physics letters. Section B, 437(3-4), 1998, pp. 398-402
Citations number
18
Categorie Soggetti
Physics
Journal title
Physics letters. Section B → ACNP
ISSN journal
03702693
Volume
437
Issue
3-4
Year of publication
1998
Pages
398 - 402
Database
ISI
SICI code
0370-2693(1998)437:3-4<398:QWLNOQ>2.0.ZU;2-Q
Abstract
We calculate the contribution of instanton - anti-instanton (I (I) ove r bar) pairs to the vacuum energy of QCD-like theories with N-f light fermions, using the saddle point method. A qualitative change of behav ior is found around N-f = 6. We discuss the relation of this phenomeno n to the mechanism of chiral symmetry breaking and the asymptotic of t he perturbative series associated with I (I) over bar contributions. ( C) 1998 Published by Elsevier Science B.V. All rights reserved.