Anomalous Couplings in γγ→W+W− at LHC and ILC

We consider sensitivities on anomalous gauge and gauge-Higgs couplings in the process γγ→W+W− at the LHC and the ILC. Within an effective Lagrangian approach we find that six anomalous couplings can be studied in this process using the normalised event distributions. We employ optimal observables to disentangle the contributions from these six anomalous couplings. Preliminary results indicate that sensitivities in γγ→W+W− at the LHC may be competitive with available results for certain gauge couplings and give direct access to two anomalous gauge-Higgs couplings. Measuring γγ→W+W− with the photon mode of the ILC could improve the corresponding sensitivities by two orders of magnitude. Polarisation of the initial photons is a valuable tool to achieve very high precisions.