Nonlocal quark model beyond mean field and QCD phase transition
Abstract
A nonlocal chiral quark model is consistently extended beyond mean field using a strict 1/Nc expansion scheme. The parameters of the nonlocal model are refitted to the physical values of the pion mass and the weak pion decay constant. The size of the 1/Nc correction to the quark condensate is carefully studied in the nonlocal and the usual local Nambu-Jona-Lasinio models. It is found that even the sign of the corrections can be different. This can be attributed to the mesonic cut-off of the local model. It is also found that the 1/Nc corrections lead to a lowering of the temperature of the chiral phase transition in comparison with the mean-field result. On the other hand, near the phase transition the 1/Nc expansion breaks down and a non-perturbative scheme for the inclusion of mesonic correlations is needed in order to describe the phase transition point.
Keywords
Cite
@article{arxiv.0910.4314,
title = {Nonlocal quark model beyond mean field and QCD phase transition},
author = {D. Blaschke and M. Buballa and A. E. Radzhabov and M. K. Volkov},
journal= {arXiv preprint arXiv:0910.4314},
year = {2010}
}
Comments
4 pages, 4 figures, talk at the 3rd Joint International Hadron Structure'09 Conference, Tatranska Strba (Slovak Republic), Aug. 30-Sept. 3, 2009