Unravelling the richness of dark sector by FASER$\nu$

TL;DR

FASERν, a new LHC experiment, aims to detect neutrinos with high precision and explore the dark sector by analyzing decay chains of light dark matter candidates, offering insights into dark matter properties.

Contribution

This paper demonstrates FASERν's potential to uncover the structure of the dark sector through neutrino detection and decay chain analysis of light dark matter models.

Findings

FASERν can detect neutrinos with high precision in the forward direction.

It can shed light on the decay chains of dark matter candidates.

The experiment offers a new way to explore the dark sector at the LHC.

Abstract

FASER$\nu$ is a newly proposed experiment which will take data in run III of the LHC during 2021-2023. It will be located in front of the FASER detector, 480~m away from the ATLAS interaction point in the forward direction. Its main goal is to detect neutrinos of all flavors produced at the interaction point with superb precision in reconstructing charged tracks. This capability makes FASER$\nu$ an ideal setup for uncovering the pattern and properties of a light dark sector. We demonstrate this capability for a well-motivated class of models with a dark matter candidate of mass around a few GeV. Dark matter annihilates to a pair of intermediate neutral particles that subsequently decay into the standard model charged fermions. We show how FASER$\nu$ can shed light on the structure of the dark sector by unravelling the decay chain within such models.