# Particle distribution in intense fields in a light-front Hamiltonian approach

## TL;DR

This paper employs the tBLFQ framework to study the non-perturbative real-time evolution of an electron in intense electromagnetic fields generated by ultra-relativistic nuclei, revealing significant higher-order effects for heavy nuclei.

## Contribution

It demonstrates the application of the tBLFQ approach to realistic strong coupling QED problems involving intense fields from ultra-relativistic nuclei, highlighting non-perturbative effects.

## Key findings

- Agreement with light-front perturbation theory for small nuclei
- Identification of higher-order contributions for heavy nuclei
- Observation of significant non-perturbative corrections in electron momentum evolution

## Abstract

We study the real-time evolution of an electron influenced by intense electromagnetic fields using the time-dependent basis light-front quantization (tBLFQ) framework. We focus on demonstrating the non-perturbative feature of the tBLFQ approach through a realistic application of the strong coupling QED problem, in which the electromagnetic fields are generated by an ultra-relativistic nucleus. We calculate transitions of an electron influenced by such electromagnetic fields and we show agreement with light-front perturbation theory when the atomic number of the nucleus is small. We compare tBLFQ simulations with perturbative calculations for nuclei with different atomic numbers, and obtain the significant higher-order contributions for heavy nuclei. The simulated real-time evolution of the momentum distribution of an electron evolving inside the strong electromagnetic fields exhibits significant non-perturbative corrections comparing to light-front perturbation theory calculations. The formalism used in this investigation can be extended to QCD problems in heavy ion collisions and electron ion collisions.