Observing doubly charged Higgs bosons in photon-photon collisions

We discuss the possibility of observing doubly charged Higgs bosons in γγ collisions. We find that one can increase the range of observability close to the kinematic limit by a judicious choice of the polarisations of the initial e−/e+ beams as well as the initial laser beam photons which are made to back-scatter from the former. We also note that, in a large region of parameter space, the generally used lepton number violating decay mode is dominated by the decay into a singly charged Higgs and a real or virtual W-boson, giving rise to a large number of fermions in the final state. This can qualitatively alter the strategy for discovering doubly-charged scalars.