Production of fermion pair and photon in polarized photon collisions

Exclusive reaction γγ→ff-γ is considered as the possible calibration process for J = 0 beams on the linear photon collider. We have analyzed the energy spectrum and total cross section dependence on the detector parameters at various initial beam helicities. It is discovered that the ratio of events on J = 0 and J = 2 beams strongly depends on the experimental cuts. We have obtained the region (the configuration of cuts) where the ratio is highest. It is the region of small cuts on polar angle, large cuts on collinear angle and high minimal energy of final-state photons. In this field the measurement of γ+γ+ beams parameters has the maximal precision. (Authors)