Finite-Temperature Gauge-Theory Effects on Calculations of the Cosmological Baryon Excess

The effects of finite-temperature gauge theory on computations of the cosmological baryon-to-entropy ratio are estimated. It is shown that a finite-temperature gauge theory may change the value of the mean net baryon number generated in a single X or X-overbar decay through changes in the Feynman integrals. For the example of a local O(n) gauge theory with one vector of Higgs fields, it is found, however, that the temperature must be extremely close to the critical temperature in order for the finite-temperature Higgs mass to differ significantly from the zero-temperature Higgs mass. It is also suggested that, due to uncertainties in X-boson masses, the presence of finite-temperature effects should also be investigated for a grand unified gauge model.