eγ and γγ colliders

The results that can be expected by eγ and γγ colliders in future are summarized. eγ and γγ colliders have many fine possibilities, and are the economical selection for utilizing future e+e- colliders more effectively. eγ and γγ colliders were proposed by former USSR researchers at the beginning of 1980s, but recently, the prospect of realizing future e+e- collision type linear accelerator projects has become high, they have become to be considered seriously as the option of remodeling them. The high energy photon beam of eγ and γγ colliders is obtained by causing Compton reverse scattering, irradiating laser beam to the electron beam of e+e- accelerators. The production of γ-beam is explained. As for the physics noteworthy in eγ colliders, abnormal gauge coupling, the formation of Higgs particles, excited leptons, lepto-quark, supersymmetric particles and top quark are explained. As the physics noteworthy in γγ colliders, the formation of Higgs particles which is most interesting in γγ colliders, abnormal gauge coupling, top quark, Yukawa coupling, Higgs pair formation and other particles are enumerated. The linear e+e- accelerators of TeV range including JLC have the performance to be remodeled to eγ and γγ colliders, and the prospect of realizing them has become high. Their possibility of realization is discussed. (K.I.)