# Light front QED, Stueckelberg field and Infrared divergence

## TL;DR

This paper demonstrates that incorporating the Stueckelberg field in light-front QED effectively cancels infrared divergences, ensuring IR finiteness in the massless gauge boson limit through explicit diagrammatic analysis.

## Contribution

It reveals the role of the Stueckelberg field in IR divergence cancellation in light-front QED, connecting gauge symmetry preservation with IR finiteness.

## Key findings

- IR divergences are canceled at leading order in self-energy diagrams.
- Stueckelberg field ensures IR finiteness in the massless limit.
- The approach parallels the Kulish-Faddeev coherent state method.

## Abstract

Stueckelberg mechanism introduces a scalar field, known as Stueckelberg field, so that gauge symmetry is preserved in the massive abelian gauge theory. In this work, we show that the role of the Stueckelberg field is similar to the Kulish and Faddeev coherent state approach to handle infrared (IR) divergences. We expect that the light-front quantum electrodynamics (LFQED) with Stueckelberg field must be IR finite in the massless limit of the gauge boson. We have explicitly shown the cancellation of IR divergences in the relevant diagrams contributing to self-energy and vertex correction at leading order.