Measurement of the muon flux at the SND@LHC experiment

The Scattering and Neutrino Detector at the LHC (SND@LHC) started taking data at the beginning of Run 3 of the LHC. The experiment is designed to perform measurements with neutrinos produced in proton-proton collisions at the LHC in an energy range between 100 GeV and 1 TeV. It covers a previously unexplored pseudo-rapidity range of 7.2<η <8.4 7.2 < η < 8.4 . The detector is located 480 m downstream of the ATLAS interaction point in the TI18 tunnel. It comprises a veto system, a target consisting of tungsten plates interleaved with nuclear emulsion and scintillating fiber (SciFi) trackers, followed by a muon detector (UpStream, US and DownStream, DS). In this article we report the measurement of the muon flux in three subdetectors: the emulsion, the SciFi trackers and the DownStream Muon detector. The muon flux per integrated luminosity through an 18 × × 18 cm ² 2 area in the emulsion is: aligned 1.5 ± 0.1(stat) × 10⁴\,fb/cm². aligned 1.5 ± 0.1 ( stat ) × 10 4 fb/cm 2 . The muon flux per integrated luminosity through a 31 × × 31 cm ² 2 area in the centre of the SciFi is: aligned 2.06± 0.01(stat)± 0.12(sys) × 10⁴ fb/cm² aligned 2.06 ± 0.01 ( stat ) ± 0.12 ( sys ) × 10 4 fb/cm 2 The muon flux per integrated luminosity through a 52 × × 52 cm ² 2 area in the centre of the downstream muon system is: aligned 2.35± 0.01(stat)± 0.10(sys) × 10⁴\,fb/cm² aligned 2.35 ± 0.01 ( stat ) ± 0.10