NEUTRINO MIXING DUE TO A VIOLATION OF THE EQUIVALENCE PRINCIPLE

Massless neutrinos will mix if their couplings to gravity are flavor d ependent, i.e., violate the principle of equivalence. Because the grav itational interaction grows with neutrino energy, the solar neutrino p roblem and the recent atmospheric neutrino data may be simultaneously explained by violations at the level of 10(-14) to 10(-17) or smaller. This possibility is severely constrained by present accelerator neutr ino experiments and will be preeminently tested in proposed long-base- line accelerator neutrino experiments.