  We formulate the conditions under which a purely bosonic theory (without
fermions) containing neutral spin-0 particles and vector (gauge) bosons
violates the CP-symmetry through the presence of CP-even and CP-odd operators
in the Lagrangian. This is done without reference to explicitly CP-violating
scalar sector of extended standard models (SM) with two or more Higgs doublets.
The Lagrangian expressed in the mass basis of the spin-0 fields can, however,
in certain cirumstances be identified with a part of the CP-violating SM with
two Higgs doublets. It is instructive to consider the manifestation of
CP-violation in the mass basis since this leads directly to suggestions of
genuine CP-signals.

High Energy Physics - Phenomenology