Detecting photon-photon scattering in vacuum at exawatt lasers

TL;DR

This paper analyzes photon-photon scattering in vacuum using QED nonlinear wave equations, proposing a feasible experiment at future exawatt laser facilities to detect this phenomenon.

Contribution

It provides a comprehensive numerical and analytical analysis of photon-photon scattering, identifying optimal experimental configurations without requiring phase coherence.

Findings

Numerical solutions confirm analytical approximations.

Optimal setup involves low power laser beam and exawatt pulse.

Proposes a practical experiment at future laser facilities.

Abstract

In a recent paper, we have shown that the QED nonlinear corrections imply a phase correction to the linear evolution of crossing electromagnetic waves in vacuum. Here, we provide a more complete analysis, including a full numerical solution of the QED nonlinear wave equations for short-distance propagation in a symmetric configuration. The excellent agreement of such a solution with the result that we obtain using our perturbatively-motivated Variational Approach is then used to justify an analytical approximation that can be applied in a more general case. This allows us to find the most promising configuration for the search of photon-photon scattering in optics experiments. In particular, we show that our previous requirement of phase coherence between the two crossing beams can be released. We then propose a very simple experiment that can be performed at future exawatt laser facilities, such as ELI, by bombarding a low power laser beam with the exawatt bump.