We consider an extension of the recent experiment with ultracold neutrons and
the quantization of its vertical motion in order to test the Weak Equivalence
Principle. We show that an improvement on the energy resolution of the
experiment may allow to establish a modest limit to the Weak Equivalence
Principle and on the gravitational screening constant. We also discuss the
influence of a possible new interaction of Nature.Comment: Revtex4, 4 pages. Discussion on the equivalence principle altered.
Bound is improve