Q-balls constructed of spinors in Lagrangians with SU(2) symmetry

Abstract

In the present work we investigate the existence and stability properties of q-balls which consist of a couple of scalar fields, forming an SU(2) doublet in a Lagrangian with a global SU(2) symmetry. We find that these spinors can form a localized and stable field configuration, if they rotate in their internal SU(2) space. We find the energy and charge of the soliton in both thin and thick-wall approximation and we prove its stability against decaying to free particles. We also find the asymptotic forms of the scalar and gauge field and the energy and charge of the configuration when the SU(2) symmetry is local. The only assumption is the smallness of the coupling constant $g$. Using numerical methods we prove the stability of the q-ball in the local case.