  The production of antihydrogen by several research groups provides the
opportunity to measure the gravitational behaviour of antimatter in the
gravitational field of the Earth. The predictions in the literature range from
normal attraction to repulsion. Applying our gravitational impact model, which
is of a purely phenomenological nature, we conclude that there will be neither
attraction nor repulsion under the assumption of a symmetric antigraviton
distribution near the antihydrogen atom. However, a very small asymmetry must
be expected and could effect the conclusion. The model, in addition, predicts
normal gravitation between antimatter and antimatter particles at large
distances, but strong repulsion at close range for matter as well as for
antimatter pairs, whereas strong attraction will result for matter-antimatter
encounters. We have further refined the model assumptions in light of recent
CERN ALPHA-g measurements that indicate a certain attraction of antihydrogen by
the gravitational field of the Earth.
