The FASER experiment at the Large Hadron Collider

TL;DR

FASER at the LHC is a novel experiment designed to detect light, weakly-interacting particles and high-energy neutrinos, with ongoing upgrades and future plans detailed in this review.

Contribution

This paper provides a comprehensive overview of FASER's design, performance, physics results, upgrades, and future plans at the LHC.

Findings

Detection of high-energy neutrinos from collider collisions

Constraints on light, weakly-interacting particles

Successful operation and ongoing upgrades of FASER

Abstract

The FASER experiment is located in the Large Hadron Collider (LHC) complex at CERN, 480 m downstream of the ATLAS collision point and aligned with the beam-collision-axis. The experiment was designed to search for light, weakly-interacting new-particles which could be produced in the LHC collisions, and, for the first-time, to study high-energy neutrinos of all flavours originating at a particle collider. This review article presents the status of FASER up to early-2026. This includes details of the FASER detector design, operation, performance and physics results, as well as briefly mentioning upgrades that have been installed since the start of FASER. In addition, future plans for the experiment are detailed.