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

Abstract

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. It is assumed that decoherence mainly affects the state ν 3 (oscillations with the atmospheric ∆m 2 ) and damping effects rapidly decrease with the neutrino energy (the decoherence parameter γ ∝ E −4 ν ). 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 model does not explain the low-energy MiniBooNE anomaly and does not resolve the LSND-KARMEN tension. The LSND signal is controlled by the 1-3 mixing angle θ 13 and, depending on the degree of damping, yields 0.0014 < sin 2 θ 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 nullresult 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.

Revisiting the quantum decoherence scenario as an explanation for the LSND anomaly

“…This explanation does not suffer from the appearance-disappearance tension of sterile neutrino models. On the other hand, with the power law energy dependence that was assumed in [10], reactor neutrinos undergo quantum decoherence after propagating distances of few cm. This implies that no oscillation due to ∆m 2 31 would be possible along the distance between near and far detectors of reactor experiments.…”

“…In view of these tensions, quantum decoherence has been suggested in the literature to explain LSND [8][9][10]. It is hypothesized that the evolution of quantum states receives a correction relative to the prediction of standard quantum mechanics.…”

“…The idea of involving quantum decoherence to explain the LSND anomaly was first proposed in [8,9]. As discussed in [10], within the framework proposed in [8,9], the decoherence effects exceed the upper bound from the NuTeV experiment [14] in which neutrinos have an average energy of 75 GeV.…”

“…Considering this observation, the so-called soft decoherence scenario was suggested in [10] as a solution to the LSND anomaly. Within this scenario, the decoherence effects rapidly decrease with neutrino energy, avoiding the NuTeV bound and leaving neutrino…”

Interim Design Report

“…The relevant symmetry [88][89][90], quantum decoherence [91,92], mass-varying neutrinos [93,94], shortcuts of sterile neutrinos in extra dimensions [95], sterile neutrino oscillations with a non-standard energy dependence [96], and sterile neutrinos plus non-standard interactions [75,97]. Some of these proposals involve very speculative physics, and many of them fail to describe all data consistently.…”