Loop Dominated Signals from Neutrino Portal Dark Matter

TL;DR

This paper explores how loop processes can dominate dark matter decay or annihilation in models with a neutrino portal, significantly impacting indirect detection signals like positrons, neutrinos, and gamma rays.

Contribution

It introduces a specific model where loop processes overshadow tree level channels in dark matter interactions via a heavy neutrino portal.

Findings

Loop processes can dominate over tree level decay channels.

Indirect detection signals are qualitatively altered.

Neutrino portal models affect gamma-ray and positron observations.

Abstract

We study scenarios where loop processes give the dominant contributions to dark matter decay or annihilation despite the presence of tree level channels. We illustrate this possibility in a specific model where dark matter is part of a hidden sector that communicates with the Standard Model sector via a heavy neutrino portal. We explain the underpinning rationale for how loop processes mediated by the portal neutrinos can parametrically dominate over tree level decay channels, and demonstrate that this qualitatively changes the indirect detection signals in positrons, neutrinos, and gamma rays.