English

Pseudoscalar and scalar meson masses at finite temperature

High Energy Physics - Phenomenology 2009-10-31 v1 High Energy Physics - Theory Nuclear Theory

Abstract

The composite operator formalism is applied to QCD at finite temperature to calculate the masses of scalar and pseudoscalar mesons. In particular the ratio of the sigma mass to the pion mass is an interesting measure of the degree of chiral symmetry breaking at different temperatures. We calculate the temperature T* at which M_sigma(T) < 2M_pi(T), above which the sigma partial width into two pions vanishes. We find T*=0.95T_c (where T_c is the critical temperature for the chiral phase transition), within the full effective potential given by the formalism. We find that an expansion a-la Landau of the effective potential around the critical point in the limit of small quark mass provides for a very good determination of T*.

Keywords

Cite

@article{arxiv.hep-ph/9810245,
  title  = {Pseudoscalar and scalar meson masses at finite temperature},
  author = {A. Barducci and R. Casalbuoni and R. Gatto and M. Modugno and G. Pettini},
  journal= {arXiv preprint arXiv:hep-ph/9810245},
  year   = {2009}
}

Comments

19 pages, Revtex, 2 Postscript figures