Neutrino decay as a possible interpretation of the MiniBooNE observation with unparticle scenario

Abstract

In a new measurement on neutrino oscillations, νμ→νe, the MiniBooNE Collaboration observes an excess of electron-like events at low energy and the phenomenon may demand an explanation that obviously is beyond the oscillation picture. We propose that the heavier neutrino, ν2, decaying into a lighter one, ν1, via the transition process νμ→νe+X, where X denotes any light products, could be a natural mechanism. The theoretical model we employ here is the unparticle scenario established by Georgi. We have studied two particular modes $\nu_{\mu}\to\nu_{e}+\mathcal{U}$ and νμ→νe+νe+νe. Unfortunately, the number coming out of the computation is too small to explain the observation. Moreover, our results are consistent with the cosmology constraint on the neutrino life time and the theoretical estimation made by other groups; therefore, we can conclude that even though neutrino decay seems plausible in this case, it indeed cannot be the source of the peak at lower energy observed by the MiniBooNE Collaboration and there should be other mechanisms responsible for the phenomenon.