Neutrino-Antineutrino Conversion from Ultralight Vector Dark Matter

TL;DR

This paper proposes that ultralight vector dark matter can induce neutrino-antineutrino conversion, with potential to explore new parameter space through astrophysical neutrino observations.

Contribution

It introduces a mechanism for neutrino-antineutrino conversion via ultralight vector dark matter and discusses its detectability in future astrophysical neutrino experiments.

Findings

Conversion effect is suppressed by neutrino mass but enhanced over long distances.

Future supernova neutrino observations could probe extremely small gauge couplings.

Parameter space beyond current experimental reach can be explored with upcoming detectors.

Abstract

We show that Majorana neutrinos convert into antineutrinos in a background of ultralight vector dark matter coupled to lepton number, such as the gauge boson of $\text{U}(1)_{B-L}$ or $\text{U}(1)_{L_i - L_j}$ with $i, j = e , \mu, \tau$. This effect is suppressed by the small neutrino mass, but the enhancement by long astrophysical baselines can enable future searches for solar and supernova neutrinos to explore uncharted parameter space. For instance, for $\text{U}(1)_{B-L}$ dark matter, the observation of a supernova neutrino burst at DUNE, Hyper-Kamiokande, and JUNO could probe gauge couplings as small as $e^\prime \sim 10^{-32} - 10^{-25}$ for dark matter masses of $m_{A^\prime} \sim 10^{-22} \ \text{eV} - 10^{-14} \ \text{eV}$, beyond the capability of other future probes.