  Recent experimental searches for neutrino mass in tritium beta decay yield a
negative value for the mass-squared of the electron neutrino. If this effect is
genuine, then it is hard to understand it using conventional particle physics
ideas as embodied in the standard model or its simple extensions that have been
widely discussed. We consider the possibility that there is a hidden anomalous
long range interaction of neutrinos that is responsible for this effect and
study the phenomenological consistency of this idea. We also discuss how such
interactions may arise in extensions of the standard model.
