Radions in a γγ collider

We study the resonance production of radions via γγ fusion in the Randall–Sundrum model. We find that the cross section of the process in the γγ mode of a linear collider (LC) can be of similar size as in the e+e− collision mode, if the radion is heavy. We consider the possible curvature-Higgs mixing in the model, and we find that the mixing should be constrained in order to avoid an unphysical state. The process γγ→φ is the main source of radions at LC near the conformal limit. We consider both the decay modes of radion with curvature-Higgs mixing and without. Our results show that the radion with mass below 800 GeV could be detected at LC with any mixing parameter and vacuum expectation value of the radion around 1 TeV.