Resonant CP Violation in MSSM Higgs Production and Decay at $\gamma \gamma$ Colliders

We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at \gamma \gamma colliders, assuming a Minimal Supersymmetric Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced by phases in the soft supersymmetry-breaking gaugino masses and third-generation trilinear squark couplings. We discuss CP asymmetries in the production and decays of \tau^+ \tau^-, {\bar b} b and {\bar t} t pairs. We find large asymmetries when two (or all three) neutral Higgs bosons are nearly degenerate with mass differences comparable to their decay widths, as happens naturally in the CP-violating MSSM for values of \tan\beta >~ 5 (30) and large (small) charged Higgs-boson masses.