Speaker
Description
Interaction between axion-like particles (ALPs) and photons can allow photons to oscillate into ALPs and pass through otherwise opaque regions. This effect is the basis of the light-shining-through-walls experiments. In this talk, I will show that such an approach can be successfully realized at astrophysical length scales using eclipsing neutron stars. During an eclipse, photon flux can partially convert into ALPs near the neutron star, traverse the companion star, and reconvert back into photons in the magnetic field of the interstellar medium. By analyzing the flux during eclipse and comparing it to the out-of-eclipse counterpart, we can put constraints on the ALP-photon coupling using this novel technique. We find that the eclipsing high mass X-ray binary, LMC X-4, is particularly well-suited for our purpose. Our results suggest that for ALPs with masses $m_a \lesssim 10^{-11}$ eV, coupling strengths as low as $g_{a\gamma} \lesssim (10^{-10} - 10^{-11}) GeV^{-1}$ could be probed. In summary, I will highlight the potential of eclipsing neutron stars as astrophysical laboratories for ALP searches.
