A light neutral Higgs boson in the framework of the general two Higgs doublet model (2HDM) is not excluded by existing data. We point out that it can be looked for at the proposed low energy $\gamma \gamma$ collider. Failure to detect one may lead to important limits on the parameters of the general 2HDM.

• Received 19 September 1996

DOI:https://doi.org/10.1103/PhysRevD.55.2774