CPT violating decoherence and LSND: a possible window to planck scale physics

Abstract

Decoherence has the potential to explain all existing neutrino data including LSND results, without enlarging the neutrino sector. This particular form of CPT violation can preserve the equality of masses and mixing angles between particle and antiparticle sectors, and still provide seizable differences in the oscillation patterns. A simplified minimal model of decoherence can explain the existing neutrino data as well as the standard three oscillation scenario, while making dramatic predictions for the upcoming experiments. Such a model can easily accomodate the LSND result but cannot fit the spectral distortions seen by KamLAND. Some comments on the order of the decoherence parameters in connection with theoretically expected values from some models of quantum-gravity are given. In particular, the quantum gravity decoherence as a primary origin of the neutrino mass differences scenario is explored, and even a speculative link between the neutrino mass-difference scale and the dark energy density component of the Universe today is drawn.

Neutrino phenomenology of very low-energy seesaw scenarios

“…This evidence of ν µ ↔ ν e oscillation requires a mass-squared difference greater than 1 eV 2 , clearly incompatible with the small mass-squared differences observed between the active neutrinos. Several mechanisms, such as CPT-violation [12,16], Lorentz invariance violation [17], quantum decoherence [18], sterile neutrino decay [19] and, of course, oscillation into sterile neutrinos have been proposed to explain this result. Here we concentrate on the last possibility.…”

Methods of approaching decoherence in the flavor sector due to space-time foam

“…This flavour bias of the foam medium, which could then be viewed as the "quantum-gravitational analogue" of the MSW effect in ordinary media. In this sense, the QG medium would be responsible for generating effective neutrino mass differences [17]. Since the charged-black holes lead to a stochastically fluctuating medium, we shall consider the formalism for the MSW effect in stochastically fluctuating media [24], where the density of electrons replaces the density of charged black hole/anti-black hole pairs.…”

“…One of the most sensitive probes of such stochastic quantum-gravity phenomena are neutrinos [7,16,17,18,19,20], in particular high-energy ones [21]. It is the point of this article to present various approaches to gravitationally-induced decoherence of matter and to classify some characteristic experimental predictions that could be falsified in current or near future neutrino experiments.…”

“…βᾱ − 1 vanishes unless the decoherence coefficients between particles and antiparticles are distinct, a case considered in [17]. Here the superscript decoh denotes the decohering piece of the relevant probability.…”

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.…”