Spontaneous and Induced Decay of Metastable Strings and Domain Walls

TL;DR

This paper analyzes the quantum and thermal decay processes of metastable strings and domain walls, deriving formulas for decay probabilities and exploring the effects of boson collisions on their destruction.

Contribution

It introduces a general formula for the probability of string and wall breakup by boson collisions, including the effects of temperature and collision number.

Findings

Decay rates at zero and low temperatures are calculated.

Destruction of strings occurs only in even-boson collisions.

Destruction of walls can occur in any boson collision.

Abstract

We consider decay of metastable topological configurations such as strings and domain walls. The transition from a state with higher energy density to a state with lower one proceeds through quantum tunneling or through thermally catalyzed quantum tunneling (at sufficiently small temperatures). The transition rate is calculated at zero temperature including the preexponential factor and also at a finite low temperature. The thermal catalysis factor is closely related to the probability (effective length) of destruction of the string (the domain wall) in collisions of the Goldstone bosons, corresponding to transverse waves on the string (wall). We derive a general formula which allows to find the probability (effective length) of a string (wall) breakup by a collision of arbitrary number of the bosons. We find that the destruction of a string only takes place in collisions of even number of the bosons, while the destruction of the wall can occur in a collision of any number of particles. We explicitly calculate the energy dependence of such processes in two-particle collisions for arbitrary relation between the energy and the largest infrared scale (the size of a critical gap).