Sphaleron transition rate in the presence of dynamical fermions - art. no.025009

We investigate the effect of dynamical fermions on the sphaleron transition rate at finite temperature for the Abelian Higgs model in one spatial dime nsion. The fermion degrees of freedom are included through bosonization. Us ing a numerical simulation, we find that massless fermions do not change th e rate within the measurement accuracy. Surprisingly, the exponential depen dence of the sphaleron energy on the Yukawa coupling is not borne out by th e transition rate, which shows a very weak dependence on the fermion mass.