Photoproduction of axion-like particles

Understand

We explore the sensitivity of photon-beam experiments to axion-like particles (ALPs) with QCD-scale masses whose dominant coupling to the Standard Model is either to photons or gluons.

• We introduce a novel data-driven method that eliminates the need for knowledge of nuclear form factors or the photon-beam flux when considering coherent Primakoff production off a nuclear target, and show that data collected by the PrimEx experiment could substantially improve the sensitivity to ALPs with $0.03 \lesssim m_a \lesssim 0.3$ GeV.
• Furthermore, we explore the potential sensitivity of running the GlueX experiment with a nuclear target and its planned PrimEx-like calorimeter.
• For the case where the dominant coupling is to gluons, we study photoproduction for the first time, and predict the future sensitivity of the GlueX experiment using its nominal proton target.