Antiparticle Contribution in the Cross Ladder Diagram for Two Boson Propagation in the Light-front

TL;DR

This paper investigates the role of antiparticle contributions in the cross ladder diagram for two-boson propagation within the light-front framework, challenging the assumption of vacuum triviality and showing both Fock sectors are essential.

Contribution

It demonstrates that both positive and negative energy Fock sectors are necessary for accurate description of two-boson propagation in light-front dynamics.

Findings

Both Fock sectors are needed for complete solutions.

Antiparticle contributions significantly affect the cross ladder diagram.

Challenges the trivial vacuum assumption in light-front theory.

Abstract

In the light-front milieu, there is an implicit assumption that the vacuum is trivial. By this " triviality " is meant that the Fock space of solutions for equations of motion is sectorized in two, one of positive energy k- and the other of negative one corresponding respectively to positive and negative momentum k+. It is assumed that only one of the Fock space sector is enough to give a complete description of the solutions, but in this work we consider an example where we demonstrate that both sectors are necessary.