Neutrino Oscillations in Dark Backgrounds

TL;DR

This paper explores how weakly-coupled dark sectors could influence neutrino oscillations, potentially explaining anomalies and offering new avenues for detecting dark matter effects through neutrino experiments.

Contribution

It introduces the idea that dark backgrounds can significantly affect neutrino propagation and proposes experimental strategies to detect or constrain these effects.

Findings

Dark backgrounds can cause measurable deviations in neutrino oscillation patterns.

Atmospheric neutrino data are highly sensitive to dark sector effects.

Future experiments like DUNE can provide complementary constraints on dark sector interactions.

Abstract

We examine scenarios in which a dark sector (dark matter, dark radiation, or dark energy) couples to the active neutrinos. For light and weakly-coupled exotic sectors we find that scalar, vector, or tensor dark backgrounds may appreciably impact neutrino propagation while remaining practically invisible to all other phenomenological probes. The dark medium may induce small departures from the Standard Model predictions or even offer an alternative explanation of neutrino oscillations. While the propagation of neutrinos is affected in all experiments, atmospheric data currently represent the most promising probe of the new physics scale. We quantify the future sensitivity of the ORCA detector of KM3NeT and the IceCube experiment and find that all exotic effects can be constrained at the level of a few percent of the Earth matter potential, with couplings mediating $\mu$-neutrino transitions being most constrained. Long baseline experiments like DUNE may provide additional complementary information on the scale of the dark sector.