Effective ALP-Photon Coupling in External Magnetic Fields

TL;DR

This paper provides a detailed calculation of quantum corrections to the ALP-photon coupling in magnetic fields, crucial for improving detection strategies in astrophysics and experiments.

Contribution

It introduces a complete one-loop fermionic correction calculation for ALP-photon interactions in arbitrary magnetic fields using advanced propagator techniques.

Findings

Exact evaluation of the triangle loop diagram

Comparison of exact results with approximation methods

Implications for ALP detection in astrophysical and laboratory settings

Abstract

We presented a complete calculation of the one-loop fermionic correction to the effective coupling between axion-like particles (ALPs) and photons within a constant, homogeneous magnetic field of arbitrary strength. This interaction, responsible for the Primakoff effect, is central to detecting axion-like particles in astrophysical settings and terrestrial experiments like helioscopes and haloscopes. Accurately predicting the interaction rate requires accounting for quantum corrections. Our work tackles this by employing magnetically field-dressed fermion propagators derived using Schwinger's proper time method and a systematic Lorentz decomposition using the Ritus basis. We evaluate the triangle loop diagram exactly, and compare it to approximations on field strength under specific assumptions.