Semiclassical analysis of axion-like particle emission via nonlinear Compton-like scattering in intense laser fields

Abstract: We investigate the production of axion-like particles through nonlinear Compton-like scattering in intense laser fields using the Baier-Katkov operator method. By explicitly constructing the eikonal spinor wave function, we utilize the semiclassical nature of relativistic electrons, which simplifies the theoretical derivation and circumvents the need to evaluate certain operator products. The electron spin-resolved axion emission rate is obtained under the local constant field approximation, with explicit calculations demonstrating that transverse acceleration dominates the radiation yields. The electron spin dependence of the axion emission rate is found to differ significantly from that of photon emission by analytically examining the asymptotic behavior of the radiation in both the weak- and strong-field limits and by numerically exploring the intermediate regime. The derived spin-resolved axion emission rate can be directly incorporated into existing semiclassical Monte Carlo algorithms developed for strong-field photon processes, enabling efficient modeling of axion-like particle generation. Our results provide promising avenues for the experimental detection and control of axion-like particles with high-intensity laser facilities.