Tracing the Interplay between Non-Thermal Dark Matter and Right-Handed Dirac Neutrinos with LHC Data

TL;DR

This paper explores how cosmological hints of extra light particles, possibly right-handed neutrinos or dark matter, relate to signals of a new heavy vector particle at the LHC, linking cosmology and collider physics.

Contribution

It investigates the connection between dark radiation, right-handed Dirac neutrinos, and heavy vector particles within a unified framework.

Findings

Cosmological data suggest the presence of extra relativistic degrees of freedom.

The model predicts detectable signals of a heavy vector meson at the LHC.

Interplay between dark radiation and collider signatures constrains new physics scenarios.

Abstract

Llight-element abundances probing big bang nucleosynthesis and precision data from cosmology probing the cosmic microwave background decoupling epoch have hinted at the presence of extra relativistic degrees of freedom. This is widely referred to as "dark radiation", suggesting the need for new light states in the UV completion of the standard model. We provide a brief and concise overview of the current observational status of such dark radiation and investigate the interplay between two possible interpretations of the extra light states: the right-handed partners of three Dirac neutrinos (which interact with all fermions through the exchange of a new heavy vector meson) and dark matter particles that were produced through a non-thermal mechanism, such us late time decays of massive relics. This model ties together cosmological indications of extra light states and the production of the heavy vector particle at the LHC.