Reconciling results of LSND, MiniBooNE and other experiments with soft decoherence

Abstract

We propose an explanation of the LSND signal via quantum-decoherence of the mass states, which leads to damping of the interference terms in the oscillation probabilities. The decoherence parameters as well as their energy dependence are chosen in such a way that the damping affects only oscillations with the large (atmospheric) $Δm^2$ and rapidly decreases with the neutrino energy. This allows us to reconcile the positive LSND signal with MiniBooNE and other null-result experiments. The standard explanations of solar, atmospheric, KamLAND and MINOS data are not affected. No new particles, and in particular, no sterile neutrinos are needed. The LSND signal is controlled by the 1-3 mixing angle $θ_{13}$ and, depending on the degree of damping, yields $0.0014 < \sin^2θ_{13} < 0.034$ at $3σ$. The scenario can be tested at upcoming $θ_{13}$ searches: while the comparison of near and far detector measurements at reactors should lead to a null-result a positive signal for $θ_{13}$ is expected in long-baseline accelerator experiments. The proposed decoherence may partially explain the results of Gallium detector calibrations and it can strongly affect supernova neutrino signals.