THERMODYNAMICAL FLUCTUATIONS OF MESON FIELDS FOR THE ZIMANYI-MOSZKOWSKI MODEL

By using the real-time Green's function method with a pair cutoff appr oximation up to the second order, the thermodynamical fluctuation effe cts of meson fields on the Zimanyi-Moszkowski model are investigated. We find that in the fluctuation effects on the effective mass of the n ucleon, the pressures are considerable in the low-baryon-density regio n and/or the high-temperature regions. The results of the Zimanyi-Mosz kowski model and the Welecka model beyond the mean-field approximation are compared.