Temperature phase transitions and stable vacuum for electroweak interactions in a magnetic field

Temperature phase transitions in a magnetic field H, determined by numerical analysis of the one-loop thermodynamical potential Ω/sup (/1/sup )/(phi2/sub c/, H, T, K), are considered in the theory of electroweak interactions. A new vacuum phase is found which is induced by the simultaneous action of the field H and the temperature T. All possible vacuum structures stable at H, Tnot =0 are described and it is shown that the character of the phase transition and the type of the resultant structure are uniquely determined by the ratio of the masses of the Higgs and W-bosons (K)/sup 1/2/ = m/M. Application of these results to cosmology is pointed out