Stability of string defects in models of non-Abelian symmetry breaking

Abstract

In this paper we describe a new type of topological defect, called a homilia string, which is stabilized through interactions with the string network. Using analytical and numerical techniques, we investigate the stability and dynamics of homilia strings, and show that they are stable in the standard electroweak model. In $\mathrm{SU}(2)\ifmmode\times\else\texttimes\fi{}U(1)$ models of symmetry breaking the intersection of two homilia strings is identified with a non-axially symmetric sphaleron. Repulsive forces between the homilia strings causes them to separate, resulting in the annihilation of the sphaleron. Furthermore, it is shown that electroweak homilia string loops cannot stabilize as vortons, which circumvents the adverse cosmological problems associated with stable loops. The consequences for GUT scale homilia strings are also discussed.