Experimental test for arion⇆photon oscillations in a homogeneous constant magnetic field

The oscillations between photon and arion in a constant homogeneous magnetic field are considered, the arion being a strictly massless pseudoscalar Goldstone particle. It is shown that using the Sun as a source of arions it is easy to surpass the astrophysical limit for its existence in a laboratory experiment, while it is practically impossible for axions. The connection between the arion {} photon oscillations in a homogeneous magnetic field and the production of photons by axions in an inhomogeneous field is discussed. The oscillations in a medium with a refraction index n{≠}1 are also considered.