UP-DOWN ASYMMETRY - A DIAGNOSTIC FOR NEUTRINO OSCILLATIONS

We propose a simple test of underground neutrino data to discriminate amongst neutrino oscillation models. It uses the asymmetry between dow nward-going events and upward-going events, for electron and muon even ts separately. Because of the symmetry of typical underground detector s, an asymmetry can be compared with calculations with little need for the intermediary of a simulation program. Furthermore, we show that t he various oscillation scenarios give rise to dramatically differing t rajectories of asymmetry versus energy for muons and electrons. This p ermits a clean distinction to be drawn between models.