NEUTRINO PHYSICS AND THE MIRROR WORLD - HOW EXACT PARITY SYMMETRY EXPLAINS THE SOLAR-NEUTRINO DEFICIT, THE ATMOSPHERIC NEUTRINO ANOMALY, AND THE LSND EXPERIMENT

Important evidence for neutrino oscillations comes from the solar neut rino deficit and the atmospheric neutrino anomaly. Further evidence fo r <(nu)over bar>(mu) --> <(nu)over bar>(e) oscillations has been repor ted at LAMPF using the LSND detector. All of these anomalies require n ew physics. We show that all of these anomalies can be explained if th e standard model is enlarged so that an unbroken parity symmetry can b e defined. This explanation holds independently of the actual model fo r neutrino masses. Thus, we argue that parity symmetry is not only a b eautiful candidate for a symmetry beyond the standard model, but it ca n also explain the known neutrino physics anomalies.