Testing Quantum Gravity via Cosmogenic Neutrino Oscillations

TL;DR

This paper investigates how quantum gravity theories could cause measurable deviations in neutrino oscillations at ultra-high energies, potentially observable with next-generation detectors like IceCube and ANITA.

Contribution

It provides approximate formulas for Planck-scale-induced deviations in neutrino oscillation lengths and assesses their observability with upcoming neutrino observatories.

Findings

Deviations may be observable for neutrinos from cosmological distances.

High-energy neutrinos could show deviations suppressed by up to the seventh power of the Planck energy.

Next-generation detectors could potentially verify quantum gravity effects on neutrino oscillations.

Abstract

Implications of some proposed theories of quantum gravity for neutrino flavor oscillations are explored within the context of modified dispersion relations of special relativity. In particular, approximate expressions for Planck-scale-induced deviations from the standard oscillation length are obtained as functions of neutrino mass, energy, and propagation distance. Grounding on these expressions, it is pointed out that, in general, even those deviations that are suppressed by the second power of the Planck energy may be observable for ultra-high-energy neutrinos, provided they originate at cosmological distances. In fact, for neutrinos in the highest energy range of EeV to ZeV, deviations that are suppressed by as much as the seventh power of the Planck energy may become observable. Accordingly, realistic possibilities of experimentally verifying these deviations by means of the next generation neutrino detectors--such as IceCube and ANITA--are investigated.