Nonperturbative evaluation of the few-body states for scalar $\chi^2\phi$ interaction

TL;DR

This paper develops an algorithm within the Feynman-Schwinger framework to compute nonperturbative bound states of up to three bodies in scalar field theory, including all relevant corrections, in the quenched approximation.

Contribution

It introduces a novel algorithm for calculating nonperturbative 1, 2, and 3-body bound states with comprehensive corrections in scalar field theory.

Findings

Simulation results for 1, 2, and 3-body states are provided.

The method includes all self energies, vertex corrections, and ladder and crossed ladder exchanges.

Calculations are performed in the quenched approximation.

Abstract

A knowledge of nonpertubative propagators is often needed when the standard perturbative methods are not applicable. An example of this is the bound state problem in field theory. While a nonperturbative result is valuable by itself, it is also an important guide for those who work on developing phenomenological models for the nonperturbative problem. The Feynman-Schwinger representation approach provides a convenient framework for calculating nonperturbative propagators. In this paper we provide an algorithm for computing 1,2, and 3 body bound states with the inclusion of all self energies, vertex corrections, ladder and crossed ladder exchanges. The calculation is done in the quenched approximation by ignoring the matter loops. We provide simulation results for 1,2 and 3-body states.