Stability of two-fermion bound states in the explicitly covariant Light-Front Dynamics

TL;DR

This paper solves covariant light-front equations for two-fermion systems with various boson exchanges, analyzing their cutoff dependence and regularization needs, with findings on scalar and pseudo-scalar exchange peculiarities.

Contribution

It introduces a method to study cutoff dependence in covariant light-front equations and provides exact solutions for different boson exchange kernels.

Findings

Results for scalar and pseudo-scalar exchange are presented.

Pseudo-scalar exchange shows unique peculiarities.

The method helps determine the need for regularization.

Abstract

The covariant light-front equations have been solved exactly for a two fermion system with different boson exchange ladder kernels. We present a method to study the cutoff dependence of these equations and to determine whether they need to be regularized or not. Results are presented for scalar and pseudo-scalar exchange. This latter furthermore exhibits some strange particularities which will be discussed.