We will search for ALPs in the MeV - TeV range through measurements at BESIII, MAMI, and MESA, in addition to the searches performed at ATLAS.
For such searches in the MeV - GeV region, a good understanding of the hadronic background channels is crucial. Therefore, the complementary measurements in two-photon processes, which are also planned in this RU, will directly impact the searches for new particles. In absence of a signal for new particles, the improved knowledge of the hadronic channels will also allow us to improve on the existing exclusion limits for ALPs and dark-sector particles.
These measurements will be complemented in the GeV - TeV range at ATLAS, where searches in the invariant mass of the di-photon system have already been used to set exclusion limits on the production of ALPs, which will be improved in the near future.