Constraints on the Baryogenesis Scale from Neutrino Masses

Abstract

Over the past few years it has been realized¹ that at temperatures above ~m _w/α_w transitions that violate baryon (B) and lepton (L) number occur rapidly since, due to the electroweak anomaly, these quantum numbers are not conserved. Indeed,

$$ \begin{array}{*{20}{c}} {{\partial _\mu }j_\mu ^B = \frac{{g_2^2}}{{32{\pi ^2}}}{n_f}(\frac{1}{3}x3)F_{\mu v}^a\tilde F_a^{\mu v}} \\ {{\partial _\mu }j_\mu ^L = \frac{{g_2^2}}{{32{\pi ^2}}}{n_f}F_{\mu v}^a\tilde F_a^{\mu v}} \\ {{\partial _\mu }j_\mu ^{B - L} = 0.} \end{array} $$