 A photo-meson is defined as "a meson ejected from an atomic nucleus as a result of the incidence of a gamma ray or other high energy photon"

Research currently focused on photo-mesons, is to yield understanding and possible use of energy, as "Photomeson production is the main energy loss for relativistic nucleons in dense radiation fields like the cosmic microwave background and the radiation fields in Gamma Ray Bursts (GRB) and jets of Active Galactic Nuclei (AGN).