Effectively flat potential in the Friedberg-Lee-Sirlin model

TL;DR

This paper investigates non-topological solitons in the Friedberg-Lee-Sirlin model, comparing effective field theory approximations with full numerical solutions to understand soliton behavior and boson condensation.

Contribution

It provides an analytical description of simplified models and validates EFT methods against numerical solutions for non-topological solitons in the FLS theory.

Findings

EFT methods accurately reproduce soliton properties

Numerical solutions confirm analytical approximations

Boson condensation on domain walls is characterized

Abstract

The Friedberg-Lee-Sirlin (FLS) model is a well-known renormalizable theory of scalar fields that provides for the existence of non-topological solitons. Since this model was proposed, numerous works have been dedicated to studying its classical configurations and its general suitability for various physical problems in cosmology, quantum chromodynamics, etc. In this paper, we study how Q-balls in effective field theory (EFT) reproduce non-topological solitons in full FLS theory. We obtain an analytical description of the simplified model and compare results with numerical calculations and perturbation theory. We also study the condensation of charged bosons on the domain wall. A full numerical solution allows us to check the EFT methods for this problem. The latter analysis is based on the application of EFT methods to significantly inhomogeneous configurations. We give an interpretation of the results in terms of the shifted boson mass and the vacuum rearrangement.