AN EFFECTIVE LAGRANGIAN WITH BROKEN SCALE AND CHIRAL-SYMMETRY .3. MESONS AT FINITE-TEMPERATURE

We investigate the finite temperature behavior of the meson sector of an effective Lagrangian which describes nuclear matter. A method is de veloped for evaluating the logarithmic terms in the effective potentia l which involves expansion and resummation; the result is written in t erms of the exponential integral. In the absence of explicit chiral sy mmetry breaking, a phase transition restores the symmetry at a tempera ture of 190 MeV; when the pion has a mass the transition is smooth. At a much higher temperature a first order phase transition restores sca le symmetry. (C) 1997 Elsevier Science B.V.