Baryon washout, electroweak phase transition, and perturbation theory
We analyze the conventional perturbative treatment of sphaleron-induced baryon number washout relevant for electroweak baryogenesis and show that it is not gauge independent due to the failure of consistently implementing the Nielsen identities order-by order in perturbation theory. We provide a gauge-independent criterion for baryon number preservation in place of the conventional (gauge-dependent) criterion needed for successful electroweak baryogenesis. We also review the arguments leading to the preservation criterion and analyze several sources of theoretical uncertainties in obtaining a numerical bound. In various beyond the standard model scenarios, a realistic perturbative treatment will likely require knowledge of the complete two-loop finite temperature effective potential and the one-loop sphaleron rate.
Additional Information© 2011 SISSA. Published for SISSA by Springer. Received: March 18, 2011; accepted: June 20, 2011; published: July 6, 2011. The authors thank S. Huber, A. J. Long and M. Shaposhnikov for valuable discussions and helpful comments. This work was supported in part by the U.S. Department of Energy contract DE-FG02-08ER41531 and by the Wisconsin Alumni Research Foundation. MJRM also thanks the Aspen Center for Physics where a portion of this work was completed.
Submitted - 1101.4665