Confronting mass-varying neutrinos with MiniBooNE

We study the proposal that mass-varying neutrinos could provide an explanation for the LSND signal for \bar\nu_mu to \bar\nu_e oscillations. We first point out that all positive oscillation signals occur in matter and that three active mass-varying neutrinos are insufficient to describe all existing neutrino data including LSND. We then examine the possibility that a model with four mass-varying neutrinos (three active and one sterile) can explain the LSND effect and remain consistent with all other neutrino data. We find that such models with a 3+1 mass structure in the neutrino sector may explain the LSND data and a null MiniBooNE result for 0.10 < \sin^2 2\theta_x < 0.30. Predictions of the model include a null result at Double-CHOOZ, but positive signals for underground reactor experiments and for \nu_\mu to \nu_e oscillations in long-baseline experiments.