Photon Production From The Scattering of Axions Out of a Solenoidal Magnetic Field

TL;DR

This paper calculates photon production from axion scattering in various magnetic field configurations, estimating conversion probabilities relevant for experiments and astrophysical phenomena, with enhanced results compared to traditional models.

Contribution

It introduces new calculations of axion-photon conversion probabilities in inhomogeneous magnetic fields, including resonance effects, and discusses potential astrophysical implications.

Findings

Conversion probabilities are 2.67 times higher than 1D estimates for QCD axions.

Resonance scattering at $E_{axion} \,\sim\, m_{axion}$ yields enhanced results.

Potential applications to solar physics and coronal heating problems.

Abstract

We calculate the total cross section for the production of photons from the scattering of axions by a strong inhomogeneous magnetic field in the form of a 2D delta-function, a cylindrical step function and a 2D Gaussian distribution, which can be approximately produced by a solenoidal current. The theoretical result is used to estimate the axion-photon conversion probability which could be expected in a reasonable experimental situation. The calculated conversion probabilities for QCD inspired axions are bigger by a factor of 2.67 (for the cylindrical step function case) than those derived by applying the celebrated 1D calculation of the (inverse) coherent Primakoff effect. We also consider scattering at a resonance $E_{axion} \sim m_{axion}$, which corresponds to the scattering from a delta-function and gives the most enhanced results. Finally, we analyze the results of this work in the astrophysical extension to suggest a way in which they may be directed to a solution to some basic solar physics problems and, in particular, the coronal heating problem.