Semiclassical Particle Spectrum of Double Sine-Gordon Model

TL;DR

This paper develops a semiclassical approach to analyze the spectrum of the non-integrable Double Sine-Gordon model, revealing various excitations, bound states, and phenomena like false vacuum decay and phase transitions.

Contribution

It introduces a semiclassical method to compute the spectrum of the Double Sine-Gordon model, complementing existing techniques and providing insights into non-perturbative phenomena.

Findings

Semiclassical method effectively predicts kink and bound state masses.

Complementary to Form Factor Perturbation Theory in certain parameter regions.

Describes false vacuum decay, resonance states, and phase transitions.

Abstract

We present new theoretical results on the spectrum of the quantum field theory of the Double Sine Gordon model. This non-integrable model displays different varieties of kink excitations and bound states thereof. Their mass can be obtained by using a semiclassical expression of the matrix elements of the local fields. In certain regions of the coupling-constants space the semiclassical method provides a picture which is complementary to the one of the Form Factor Perturbation Theory, since the two techniques give information about the mass of different types of excitations. In other regions the two methods are comparable, since they describe the same kind of particles. Furthermore, the semiclassical picture is particularly suited to describe the phenomenon of false vacuum decay, and it also accounts in a natural way the presence of resonance states and the occurrence of a phase transition.