Can $γγ\rightarrow Z_L Z_L$ serve as a probe of the electroweak symmetry breaking sector ?

Abstract

We investigate the feasibility of distinguishing among different models of electroweak symmetry breaking by studying the process $γγ\rightarrow Z_L Z_L$ at photon colliders. For models with a low mass Higgs-like scalar resonance, the $s$-channel contribution provides a distinct resonance structure and large cross sections. However, the absence of a resonance structure in the cross section for the above process does not discriminate in principle between the existence of either a heavy Higgs boson or a vector resonance of a non-linearly realized symmetry.