New Constraints on the Coupling of Axion-Like-Particles with Photons Via Inverse Primakoff Scattering

Axions-like-particles (ALP) naturally appear in many extensions of the Standard Model of particle physics, and are viable candidates to Cosmological Dark Matter. The Sun can also be an astrophysical source of ALP, produced through the Primakoff process. ALPs can leave their signatures at detector through the inverse Primakoff (IP) scattering. We identify inelastic channels to the IP-processes due to atomic excitation and ionization. Their cross sections are derived with full electromagnetic fields of atomic charge and current densities, and computed by well-benchmarked atomic many body methods. Using the TEXONO and XENON1T experiments, we derive new upper constraint in \(g_{a\gamma \gamma }\) - \(m_{a}\) parameter space.