  We identify a number of problematic aspects of current classical and quantum
theories of antimatter; we introduce a new mathematical formalism which is an
antiautomorphic image of that of matter equivalent to charge conjugation at the
operator level, but applicable from Newton's equations to quantum mechanics; we
show that the emerging new theory of antimatter recovers known experimental
data on electroweak interactions; we finally identity the following predictions
of the theory: 1) reversal in the field of matter of the gravitational
curvature (antigravity) for stable antiparticles and their bound states, such
as the anti-hydrogen atom; 2) conventional (attractive) gravity for a bound
state of an elementary particle and its antiparticle, such as the positronium;
and 3) prediction that the anti- hydrogen atom emits a new photon which
coincides with the conventional photon for all electroweak interactions but
experiences repulsion in the gravitational field of matter.
