Flavor ratios of extragalactical neutrinos and neutrino shortcuts in extra dimensions

TL;DR

This paper explores how extra-dimensional shortcuts affecting sterile neutrino dispersion relations can alter the flavor ratios of high-energy extragalactic neutrinos detected by IceCube, revealing potential new physics beyond the Standard Model.

Contribution

It introduces two models of ADR effects on neutrino oscillations in extra dimensions and analyzes their impact on astrophysical neutrino flavor ratios.

Findings

Resonant ADR effects can significantly suppress certain neutrino flavors at high energies.

Active-sterile oscillations with constant ADR potential modify flavor ratios.

Potential to use flavor ratios as probes of extra-dimensional physics.

Abstract

The recent measurement of high energy extragalactic neutrinos by the IceCube Collaboration has opened a new window to probe non-standard neutrino properties. Among other effects, sterile neutrino altered dispersion relations (ADRs) due to shortcuts in an extra dimension can significantly affect astrophysical flavor ratios. We discuss two limiting cases of this effect, first active-sterile neutrino oscillations with a constant ADR potential and second an MSW-like resonant conversion arising from geodesics oscillating around the brane in an asymmetrically warped extra dimension. We demonstrate that the second case has the potential to suppress significantly the flux of specific flavors such as $\nu_\mu$ or $\nu_\tau$ at high energies.