Determining the t bar t and ZZ Couplings of a Neutral Higgs Boson of Arbitrary CP Nature at the Next Linear Collider

The optimal procedure for extracting the coefficients of different components of an observable which takes the form of unknown coefficients times functions of known form is developed. When applied to e+e-→t bar t+ Higgs production at √s=1 TeV and integrated luminosity times efficiency of 50 fb-1, we find that the t bar t→ Higgs CP-even and CP-odd couplings and, to a lesser extent, the ZZ→Higgs (CP-even) coupling can be extracted with reasonable errors, assuming the Higgs sector parameter choices yield a significant production rate. The composition of a mixed-CP Higgs eigenstate can be determined with sufficient accuracy that a standard-model-like CP-even Higgs boson can be distinguished from a purely CP-odd Higgs boson at a high level of statistical significance, and vice versa. copyright 1996 The American Physical Society