Lorentz noninvariant neutrino oscillations without neutrino mass

Abstract

The bicycle model of Lorentz noninvariant neutrino oscillations without neutrino masses naturally predicts maximal mixing and a 1/E dependence of the oscillation argument for $\nu_\mu \to \nu_\tau$ oscillations of atmospheric and long-baseline neutrinos, but cannot also simultaneously fit the data for solar neutrinos and KamLAND. We examine all nineteen possible structures of the Standard Model Extension for Lorentz noninvariant oscillations of massless neutrinos that naturally have a 1/E dependence at high neutrino energy. Due to the lack of any evidence for direction dependence, we consider only direction-independent oscillations. Although we find a number of models with a 1/E dependence for atmospheric and long-baseline neutrinos, none can also simultaneously fit solar and KamLAND data.