The evaporation of Q-balls

In extended electroweak models with scalar fields carrying lepton number, it is possible for these fields to form extended objects of the Q-ball sort. In general, these are destabilised by the Yukawa coupling of the scalar to neutrinos. This decay process takes place only on the surface of the object, not in the interior. Thus the Q-balls evaporate away. We set up the general theory of this process, find an absolute upper bound for the evaporation rate, and explicitly compute the rate in a simple case. (orig.)