Observing neutrinos at CMS and ATLAS with a gaseous fixed target concept

The SHIFT@LHC proposal introduced a novel shifted gaseous fixed-target concept at the LHC to search for exotic particles. In this article, we explore an entirely different physics opportunity enabled by this setup: the observation of neutrinos in general-purpose LHC detectors. Using simulations of proton-gas collisions, hadron propagation, and neutrino interactions, we estimate that O ( 10 4 ) muon-neutrino and O ( 10 3 ) electron-neutrino interactions, with energies from 20 GeV to 1 TeV, would occur in the CMS and ATLAS detectors with 1% of the LHC Run-4 integrated luminosity ( ≈ 4 × 10 25 protons on target). This unique configuration provides access to hadron production in the pseudorapidity range 5 < η < 8 , complementary to existing LHC detectors. If realized, this would mark the first detection of neutrinos in a hadron collider detector, demonstrating the feasibility of such measurements in this experimental environment.