We have examined the saturation of anomalous Ward identities by the low-lying pseudoscalars TO, 7, and 7' to determine the sizes of 7'-7, TO-^, and TO-7' mixing angles. The 7'-7 mixing angle turns out to be about -20" which is consistent with the recent findings. Our estimate for the aO-7 mixing angle shows that it could be bigger than the older value obtained from the p-w mixing, baryon mass splittings, and kaon mass difference.

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We estimate the sizes of η - η', η - π0 and η' - π0 mixing angles by solving the Ward-identities in QCD and taking into account SU(3) violation of the quark condensates. Our results are compared with those obtained by treating the quark condensates SU(3) symmetric.

The purpose of this paper is to study the bulk properties of nucleon-antinucleon plasma as a function of temperature in the relativistic Hartree approximation which takes into account the contribution of vacuum-fluctuation energy using both Walecka's model and the chirally symmetric a model. This paper is an extension of previous work of Theis et al. based on Walecka's model and carried out in the mean-field-theory approximation. In our calculation the effective nucleon mass M* can be both greater and less than the free-nucleon mass M. When we consider the M* < M branch of the solution, we find that there is a peak in the specific heat of the plasma divided by its limiting analytic Stefan-Boltzmann form around T=225 MeV in the case of Walecka's model. This fact may be interpreted by saying that the hadron phase of nuclear matter alone undergoes an abrupt change in the bulk properties around p, -0 and T=225 MeV. We also find the surprising result that the energy density corresponding to the M * > M branch of the solution is less than that of the M * < M branch of solution beyond a certain temperature. In the case of the a model, the solution for nonzero M * < M does not exist beyond a certain temperature.

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