First Direct Observation of Collider Neutrinos with FASER at the LHC
Creators: name: FASER Collaboration
name: Abreu, Henso
name: Anders, John
name: Antel, Claire
name: Ariga, Akitaka
name: Ariga, Tomoko
name: Atkinson, Jeremy
name: Bernlochner, Florian U.
name: Blesgen, Tobias
name: Boeckh, Tobias
name: Boyd, Jamie
name: Brenner, Lydia
name: Cadoux, Franck
name: Casper, David W.
name: Cavanagh, Charlotte
name: Chen, Xin
name: Coccaro, Andrea
name: Desai, Ansh
name: Dmitrievsky, Sergey
name: D'Onofrio, Monica
name: Favre, Yannick
name: Fellers, Deion
name: Feng, Jonathan L.
name: Fenoglio, Carlo Alberto
name: Ferrere, Didier
name: Gibson, Stephen
name: Gonzalez-Sevilla, Sergio
name: Gornushkin, Yuri
name: Gwilliam, Carl
name: Hayakawa, Daiki
name: Hsu, Shih-Chieh
name: Hu, Zhen
name: Iacobucci, Giuseppe
name: Inada, Tomohiro
name: Jakobsen, Sune
name: Joos, Hans
name: Kajomovitz, Enrique
name: Kawahara, Hiroaki
name: Keyken, Alex
name: Kling, Felix
name: Köck, Daniela
name: Kose, Umut
name: Kotitsa, Rafaella
name: Kuehn, Susanne
name: Lefebvre, Helena
name: Levinson, Lorne
name: Li, Ke
name: Liu, Jinfeng
name: MacDonald, Jack
name: Magliocca, Chiara
name: Martinelli, Fulvio
name: McFayden, Josh
name: Milanesio, Matteo
name: Mladenov, Dimitar
name: Moretti, Théo
name: Munker, Magdalena
name: Nakamura, Mitsuhiro
name: Nakano, Toshiyuki
name: Nessi, Marzio
name: Neuhaus, Friedemann
name: Nevay, Laurie
name: Otono, Hidetoshi
name: Pang, Hao
name: Paolozzi, Lorenzo
name: Petersen, Brian
name: Pietropaolo, Francesco
name: Prim, Markus
name: Queitsch-Maitland, Michaela
name: Resnati, Filippo
name: Rokujo, Hiroki
name: Ruiz-Choliz, Elisa
name: Sabater-Iglesias, Jorge
name: Sato, Osamu
name: Scampoli, Paola
name: Schmieden, Kristof
name: Schott, Matthias
name: Sfyrla, Anna
name: Shively, Savannah
name: Takubo, Yosuke
name: Tarannum, Noshin
name: Theiner, Ondrej
name: Torrence, Eric
name: Tufanli, Serhan
name: Vasina, Svetlana
name: Vormwald, Benedikt
name: Wang, Di
name: Welch, Eli
name: Zambito, Stefano
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report the first direct observation of neutrino interactions at a particle collider experiment. Neutrino candidate events are identified in a 13.6 TeV center-of-mass energy $pp$ collision data set of 35.4 fb${}^{-1}$ using the active electronic components of the FASER detector at the Large Hadron Collider. The candidates are required to have a track propagating through the entire length of the FASER detector and be consistent with a muon neutrino charged-current interaction. We infer $153^{+12}_{-13}$ neutrino interactions with a significance of 16 standard deviations above the background-only hypothesis. These events are consistent with the characteristics expected from neutrino interactions in terms of secondary particle production and spatial distribution, and they imply the observation of both neutrinos and anti-neutrinos with an incident neutrino energy of significantly above 200 GeV.
description: Submitted to PRL on March 24 2023