Off-shell OPERA neutrinos

Abstract

In the OPERA experiment, superluminal propagation of neutrinos can occur if one of the neutrino masses is extremely small. However the effect only has appreciable amplitude at energies of order this mass and thus has negligible overlap with the multi-GeV scale of the experiment.

Comments: Typos corrected. Expanded to include discussion of boosted wave packets similar to Naumov & Naumov, and explanation for why causality is not threatened. References added