Spin-Dependent Axion Generation with Controllable Emission Angles in Strong Laser Fields

TL;DR

This paper proposes a method to generate and control axion emission angles using spin-polarized electrons and ultraintense lasers, enabling laboratory searches for axion-electron interactions.

Contribution

It introduces a spin-resolved Monte Carlo framework to model axion production in strong laser fields, demonstrating controllable axion emission directions based on electron polarization.

Findings

Dense, collimated axion beams with high coupling sensitivity can be produced within femtoseconds.

Axion emission angles can be tuned by adjusting electron and laser polarization.

The method offers a new way to manipulate axion trajectories for experimental searches.

Abstract

We investigate axion production in the collision between a spin-polarized relativistic electron beam and an ultraintense laser pulse. A spin-resolved Monte Carlo framework is developed to model axion-electron and axion-photon couplings in arbitrary electromagnetic fields, using quantum emission probabilities under the local constant field approximation. Owing to spin-dependent asymmetries in radiation probability, the emitted axions acquire a characteristic angular deflection tied to the initial electron polarization. This spin-dependent asymmetry enables control over the axion emission direction by adjusting the polarization of the electron beam and laser field. Simulations show that a dense and collimated axion beam ($\sim 10^{10} g_{ae}^2$) with a tunable deflection angle ($\sim$ mrad) can be produced within tens of femtoseconds using current laser technology. Our results establish a novel mechanism for manipulating axion trajectories and open a promising route toward laboratory-based searches for the axion-electron coupling.