Study of gamma gamma -> W_L W_L and gamma gamma -> Z_L Z_L reactions   with Chiral Lagrangians
  We analyze the effects of a strongly interacting symmetry breaking sector of the Standard Model in $\gamma \gamma -> W_L^+ W_L^-$ and $\gamma \gamma -> Z_L Z_L$ reactions at TeV energies by using Chiral Lagrangians and Chiral Perturbation Theory. We find significant deviations from the Standard Model predictions for the differential cross sections at high invariant mass of the gauge bosons pair. We study the experimental signals that could be obtained in a high energy and high luminosity dedicated $\gamma\gamma$ collider and estimate the sensitivity that such experiments could reach to the values of the effective lagrangian parameters. 
Maria Herrero and Ester Ruiz-Morales