Semi-classical spectrum of the Homogeneous sine-Gordon theories

TL;DR

This paper derives the semi-classical spectrum of Homogeneous sine-Gordon theories linked to any compact simple Lie group, revealing a spectrum composed solely of solitons with both stable and unstable particles.

Contribution

It provides the first semi-classical spectrum analysis for these theories, showing solitons as the only spectrum components and constructing explicit one-soliton solutions.

Findings

Spectrum consists entirely of solitons.

Presence of both stable and unstable particles.

Construction of one-soliton solutions via embeddings.

Abstract

The semi-classical spectrum of the Homogeneous sine-Gordon theories associated with an arbitrary compact simple Lie group G is obtained and shown to be entirely given by solitons. These theories describe quantum integrable massive perturbations of Gepner's G-parafermions whose classical equations-of-motion are non-abelian affine Toda equations. One-soliton solutions are constructed by embeddings of the SU(2) complex sine-Gordon soliton in the regular SU(2) subgroups of G. The resulting spectrum exhibits both stable and unstable particles, which is a peculiar feature shared with the spectrum of monopoles and dyons in N=2 and N=4 supersymmetric gauge theories.