Higgs Production: CP Studies in e-e- Collisions
  We review the production of scalar Higgs-like particles in high-energy electron-electron collisions, via the fusion of electroweak gauge bosons. The emphasis is on how to distinguish a CP-even from a CP-odd Higgs particle. Among the more significant differences, we find that in the CP-odd case, the Higgs spectrum is much harder, and the dependence of the total cross section on the product of the polarizations of the two beams is much stronger, than in the CP-even case. We also briefly discuss parity violation, and the production of charged Higgs bosons. 
C. A. Boe, O. M. Ogreid, P. Osland (Bergen) and Jian-zu Zhang (ECUST,   Shanghai)