Radial excitations of Q-balls, and their D-term

TL;DR

This paper investigates the structure and properties of radial excitations of Q-balls, focusing on their energy-momentum tensor and D-term, revealing regular scaling patterns and confirming the negativity of the D-term for excited states.

Contribution

It provides the first detailed study of the D-term for excited Q-ball states and demonstrates regular scaling behaviors in their properties with excitation number N.

Findings

D-term for excited Q-balls is negative, consistent with ground state results.

Properties of solutions scale regularly with excitation number N.

Numerical analysis covers excitations from N=1 to N=23.

Abstract

We study the structure of the energy-momentum tensor of radial excitations of Q-balls in scalar field theories with U(1) symmetry. The obtained numerical results for the $1\le N \le 23$ excitations allow us to study in detail patterns how the solutions behave with N. We show that although the fields and energy-momentum tensor densities exhibit a remarkable degree of complexity, the properties of the solutions scale with N with great regularity. This is to best of our knowledge the first study of the D-term d1 for excited states, and we demonstrate that it is negative --- in agreement with results from literature on the d1 of ground state particles.