Peláez Sagredo, José Ramón2023-06-202023-06-202002-11-010556-282110.1103/PhysRevD.66.096007https://hdl.handle.net/20.500.14352/59870©2002 The American Physical Society. The author thanks A. Dobado, A. Gómez Nicola and E. Oset for useful comments, and support from the Spanish CICYT projects FPA2000 0956 and BFM2000 1326, as well as the Marie Curie fellowship through Grant No. MCFI-2001-01155.The SU(2) and SU(3) chiral phase transitions in a gas made of pions, kaons, and etas are studied within the framework of chiral perturbation theory. We describe the temperature dependence of the quark condensates by using the meson meson scattering phase shifts in a second order virial expansion. In particular, the SU(3) formalism yields a somewhat lower melting temperature for the nonstrange condensates than within SU(2), and also predicts that the strange condensate melting is slower than that of the nonstrange, due to the different strange and nonstrange quark masses.engjournal articlehttp://dx.doi.org/http://dx.doi.org/10.1103/PhysRevD.66.096007http://journals.aps.orgopen access51-73One-loopForm-factorsMeson interactionsVirial expansionQuark massPion gasScatteringQcdUnitarizationLagrangiansFísica-Modelos matemáticosFísica matemática