Results from the OPAL experiment using photonic final states

Event topologies characterized by photonic final states at LEP2 energies are analyzed by the OPAL Collaboration in order to study gauge boson couplings. Results on neutral triple gauge boson couplings are presented, based on e+e−→Zγ events collected at 189 GeV. e+e−→W+W−γ and e+e−→νν̄γ events are studied to measure charged quartic gauge boson couplings, whereas neutral quartic boson vertices are investigated by using e+e−→qq̄γγ events. Searches for Higgs bosons with an enhanced coupling to photon pairs are also based on event topologies characterized by two photons in the final state, at center-of-mass energies between 91 and 108 GeV. The prospects for these analyses at future colliders are discussed.