# Neutrino Portals to Dark Matter

## TL;DR

This paper investigates the feasibility of dark matter interactions primarily occurring via neutrinos, proposing models where neutrino portals dominate dark matter phenomenology and discussing experimental constraints and future detection prospects.

## Contribution

It introduces two neutrino portal models with gauge invariance, demonstrating their potential to dominate dark matter interactions and analyzing current and future experimental sensitivities.

## Key findings

- Neutrino interactions can dominate dark matter phenomenology in certain models.
- Current neutrino detectors already set strong constraints on these models.
- Future experiments could probe the relevant dark matter-neutrino cross sections.

## Abstract

We explore the possibility that dark matter interactions with Standard Model particles are dominated by interactions with neutrinos. We examine whether it is possible to construct such a scenario in a gauge invariant manner. We first study the coupling of dark matter to the full lepton doublet and confirm that this generally leads to the dark matter phenomenology being dominated by interactions with charged leptons. We then explore two different implementations of the neutrino portal in which neutrinos mix with a Standard Model singlet fermion that interacts directly with dark matter through either a scalar or vector mediator. In the latter cases we find that the neutrino interactions can dominate the dark matter phenomenology. Present neutrino detectors can probe dark matter annihilations into neutrinos and already set the strongest constraints on these realisations. Future experiments such as Hyper-Kamiokande, MEMPHYS, DUNE, or DARWIN could allow to probe dark matter-neutrino cross sections down to the value required to obtain the correct thermal relic abundance.