Neutrino Up-scattering via the Dipole Portal at Forward LHC Detectors

TL;DR

This paper explores how forward LHC detectors can use neutrino up-scattering via the dipole portal to discover or constrain sterile neutrinos and new physics at TeV energies.

Contribution

It introduces the potential of future forward detectors at the LHC to probe sterile neutrinos through dipole interactions, expanding the search for new physics beyond current limits.

Findings

Forward detectors can test sterile neutrinos up to 1 GeV.

Neutrino up-scattering provides new parameter space coverage.

Displaced photon signatures can indicate sterile neutrino decay.

Abstract

The significant neutrino flux at high rapidity at the LHC motivates dedicated forward detectors to study the properties of neutrinos at TeV energies. We investigate magnetic dipole interactions between the active neutrinos and new sterile states at emulsion and liquid argon experiments that could be located in a future Forward Physics Facility (FPF) downstream of the ATLAS interaction point. The up-scattering of neutrinos off electrons produces an electron recoil signature that can probe new regions of parameter space at the High Luminosity LHC (HL-LHC), particularly for liquid argon detectors due to low momentum thresholds. We also consider the decay of the sterile neutrino through the dipole operator, which leads to a photon that could be displaced from the production vertex. FPF detectors can test sterile neutrino states as heavy as 1 GeV produced through the dipole portal, highlighting the use of high energy LHC neutrinos as probes of new physics.