It is shown that in the Einstein-Yang-Mills (EYM) theory, as well as in the pure flat space Yang-Mills (YM) theory, there always exists an opportunity to pass over the potential barrier separating homotopically distinct vacuum sectors, because the barrier height may be arbitrarily small. However, at low energies all the overbarrier histories are suppressed by the destructive interference. In the pure YM theory the situation remains the same for any energies. In the EYM theory on the other hand, when the energy is large and exceeds the ground state EYM sphaleron mass, the constructive interference occurs instead. This means that in the extreme high energy limit the exponential suppression of the fermion number violation in pure YM theory is removed due to gravitational effects.
- Pub Date:
- January 1994
- High Energy Physics - Theory;
- General Relativity and Quantum Cosmology
- (minor misprints in Eqs.(31),(33) have been corrected) 39 LaTeX pages, 3 postscript figures are available on request from firstname.lastname@example.org, Preprint ZU-TH 1/94