Pion dispersion relation at finite temperature in the linear sigma model from chiral Ward identities
Abstract
We develop one-loop effective vertices and propagators in the linear sigma model at finite temperature satisfying the chiral Ward identities. We use these in turn to compute the pion dispersion relation in a pion medium for small momentum and temperatures on the order of the pion mass at next to leading order in the parameter m_pi^2/4pi^2f_pi^2 and to zeroth order in the parameter (m_pi/m_sigma)^2. We show that this expansion reproduces the result obtained from chiral perturbation theory at leading order. The main effect is a perturbative, temperature-dependent increase of the pion mass. We find no qualitative changes in the pion dispersion curve with respect to the leading order behavior in this kinematical regime.
Keywords
Cite
@article{arxiv.hep-ph/0001045,
title = {Pion dispersion relation at finite temperature in the linear sigma model from chiral Ward identities},
author = {Alejandro Ayala and Sarira Sahu and Mauro Napsuciale},
journal= {arXiv preprint arXiv:hep-ph/0001045},
year = {2009}
}
Comments
9 pages, 4 figures uses revtex and epsfig. Expanded discussion, new references added, typos corrected. To appear in Phys. Lett. B