Neutrino beam-dump experiment with FASER at the LHC

TL;DR

The paper explores the potential of the FASER experiment at the LHC to conduct neutrino physics studies and search for BSM particles, highlighting its diverse detection strategies and enhanced sensitivity during the High-Luminosity phase.

Contribution

It introduces new search strategies for BSM particles using neutrino interactions at FASER, expanding the experimental sensitivity with multiple detection signatures.

Findings

FASER can detect heavy neutral leptons via multiple signatures.

Sensitivity to BSM particles is significantly improved during HL-LHC.

Various detection channels extend the physics reach of FASER 2.

Abstract

The neutrino physics program at the LHC, which will soon be initiated by the FASER experiment, will provide unique opportunities for precision studies of neutrino interaction vertices at high energies. This will also open up the possibility to search for beyond the standard model (BSM) particles produced in such interactions in the specific high-energy neutrino beam-dump experiment. In this study, we illustrate the prospects for such searches in models with the dipole or $Z^\prime$ portal to GeV-scale heavy neutral leptons. To this end, we employ both the standard signature of new physics that consists of a pair of oppositely-charged tracks appearing in the decay vessel, and the additional types of searches. These include high-energy photons and single scattered electrons. We show that such a variety of experimental signatures could significantly extend the sensitivity reach of the future multi-purpose FASER 2 detector during the High-Luminosity phase of the LHC.