Conformal Freeze-In from Neutrino Portal

TL;DR

This paper explores a dark matter production mechanism via a conformal field theory interacting through the neutrino portal, which can account for observed relic density and neutrino masses, with potential X-ray detectability.

Contribution

It introduces a novel conformal freeze-in model where a CFT-based dark sector interacts through the neutrino portal, linking dark matter production to neutrino mass generation.

Findings

The model reproduces the observed dark matter relic density.

It is consistent with current X-ray constraints.

Potential for future X-ray detection of dark matter signals.

Abstract

We study a scenario where a dark sector, described by a Conformal Field Theory (CFT), interacts with the Standard Model through the neutrino portal. In this setup, conformal invariance breaks below the electroweak scale, causing the theory to transition into a confined (hadronic) phase. One of the hadronic excitations in this phase can act as dark matter. In the "Conformal Freeze-In" cosmological framework, the dark sector is populated through interactions with the Standard Model at temperatures where it retains approximate conformal symmetry. The dark matter relic density depends on the CFT parameters, such as the dimension of the operator coupled to the Standard Model. We demonstrate that this model can reproduce the DM relic density and meet all observational constraints. The same neutrino portal interaction may also generate masses for the active neutrinos. The dark matter candidate could either be a pseudo-Goldstone boson (PGB) or a composite fermion with the quantum numbers of a sterile neutrino. In the latter case, the model is consistent with the current X-ray constraints, and may be detectable with future X-ray observations.