GAMA, F. J. A.; http://lattes.cnpq.br/9165831518410079; GAMA, Fernando José de Almeida.
Résumé:
We study the meson’s matter π+ and π− at finite temperature and zero chemical potential in the relativistic mean field theory (MFT) including the mesons exchange ρ and σ among π+ and π−. We get the mean ρµ field is zero. We obtain two solutions for the σ field for each temperature, but the temperatures above 80 MeV, we don’t get any solution, this leads us to conclude that the Bose-Einstein’s temperature of pion’s matter is 80 MeV. We analyze the behavior of the effective pion’s mass, the effective sigma’s mass, pressure, energy density and energy per pion, all of them as a function of temperature. For each value of the σ field was obtained two different values for the scalar density resulting in four distinct solutions for the: effective pion’s mass, effective sigma’s mass, energy density, pressure and particles’s number. Among these four solutions, two states represent difficulty in physical interpretation, situation that provide negative pressure, so are not considered in this work, and the others two states represent: a matter that resembles a gas and the other likes a liquid state.