Neutrino detection without neutrino detectors: Discovering collider neutrinos at FASER with electronic signals only

Abstract

The detection of collider neutrinos will provide new insights about neutrino production, propagation, and interactions at TeV energies, the highest human-made energies ever observed. During run 3 of the LHC, the FASER experiment is expected to detect roughly ${10}^{4}$ collider neutrinos using its emulsion-based neutrino detector $\mathrm{FASER}\ensuremath{\nu}$. In this study, we show that, even without processing the emulsion data, low-level input provided by the electronic detector components of FASER and $\mathrm{FASER}\ensuremath{\nu}$ will be able to establish a $5\ensuremath{\sigma}$ discovery of collider neutrinos with as little as $5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity. These results foreshadow the possible early discovery of collider neutrinos in LHC run 3.