First results of LHC neutrinos with FASERnu

Abstract

FASER is aiming to detect neutral Beyond Standard Model particles and neutrinos from LHC ATLAS p-p collision point. Studies of hadron production with high-energy proton beams have been basic inputs to understand the cosmic-ray spectra observed on the earth. While the Ultra-High-Energy Cosmic Ray (UHECR) studies gave discrepancy in number of muons or cosmic ray composition from expectation and it have been a hot topics in the field and called Muon Puzzle. The FASER detector located at 480 m away in the forward direction of 14 TeV p-p collision point. As it corresponds to 100 PeV proton interactions in fixed target mode, a precise measurement by FASER would provide information relevant to PeV-scale cosmic rays. Study with three flavours neutrinos with the dedicated neutrino detector (FASER 𝜈 ) would shed light on the unresolved Muon Puzzle. FASER has started taking data in Run 3 of the LHC operation (2022-2025). Here the first results on neutrino analysis from the 2022 run and its prospects are reported.