Probing the Higgs mechanism via $\gamma\gamma\to W^+W^-$
  We investigate the sensitivity of the reaction $\gamma\gamma\to W^+W^-$ to the Higgs sector based on the complete one-loop corrections in the minimal Standard Model and the gauged non-linear $\sigma$-model. While this sensitivity is very strong for the suppressed cross-section of equally polarized photons and longitudinal W bosons, it is only marginal for the dominant mode of transverse polarizations. The corrections within the $\sigma$-model turn out to be UV-finite in accordance with the absence of $\log\MH$ terms in the Standard Model with a heavy Higgs boson. 
A.Denner, S.Dittmaier and R.Schuster