Analytical and numerical properties of Q-balls

TL;DR

This paper investigates the properties of Q-balls, a type of non-topological soliton, using analytical and numerical methods across different potentials, revealing how their characteristics vary between thick- and thin-wall regimes.

Contribution

It provides analytical criteria for Q-ball stability in the thick-wall limit and compares properties across polynomial and logarithmic potentials.

Findings

Q-balls exhibit different properties in thick- and thin-wall limits.

Analytical criteria for stability in the thick-wall limit are derived.

Evaporation rates increase as Q-ball charge decreases.

Abstract

Stable non-topological solitons, Q-balls, are studied using analytical and numerical methods. Three different physically interesting potentials that support Q-ball solutions are considered: two typical polynomial potentials and a logarithmic potential inspired by supersymmetry. It is shown that Q-balls in these potentials exhibit different properties in the thick-wall limit where the charge of a Q-ball is typically considerably smaller than in the thin-wall limit. Analytical criteria are derived to check whether stable Q-balls exists in the thick-wall limit for typical potentials. Q-ball charge, energy and profiles are presented for each potential studied. Evaporation rates are calculated in the perfect thin-wall limit and for realistic Q-ball profiles. It is shown that in each case the evaporation rate increases with decreasing charge.