Observation of Collider Neutrinos without Final State Muons with the SND@LHC Experiment

We report the observation of neutrino interactions without final state muons at the LHC, with a significance of $ 6.4\sigma $. A dataset of proton-proton collisions at $ \sqrt{s}=13.6\text{}\text{}\mathrm{TeV}$ collected by SND@LHC in 2022 and 2023 is used, corresponding to an integrated luminosity of $ 68.6\text{}\text{}{\mathrm{fb}}^{-1}$. Neutrino interactions without a reconstructed muon are selected, resulting in an event sample consisting mainly of neutral-current and electron neutrino charged-current interactions in the detector. After selection cuts, 9 neutrino interaction candidate events are observed with an estimated background of 0.32 events.