Stabilisation of semilocal strings by dark scalar condensates

TL;DR

This paper demonstrates that dark scalar condensates, coupled via Higgs portal interactions and gauge kinetic mixing, can significantly stabilize semilocal strings that are otherwise unstable, with implications for dark matter models.

Contribution

It introduces a mechanism where dark scalar fields stabilize semilocal strings through Higgs portal couplings and gauge kinetic mixing, a novel approach in dark matter and string stability research.

Findings

Dark scalar condensates stabilize semilocal strings.

Higgs-portal couplings enhance string stability.

Gauge kinetic mixing contributes to stabilization.

Abstract

Semilocal and electroweak strings are well-known to be unstable against unwinding by the condensation of the second Higgs component in their cores. A large class of current models of dark matter contains dark scalar fields coupled to the Higgs sector of the Standard Model (Higgs portal) and/or dark U(1) gauge fields. It is shown, that Higgs-portal-type couplings and a gauge kinetic mixing term of the dark U(1) gauge field have a significant stabilising effect on semilocal strings in the "visible" sector.