Measurement of the muon neutrino charged-current cross section with SND@LHC

Abstract

We report a measurement of the muon neutrino charged-current (CC) interaction cross section on tungsten using the electronic detectors of the SND@LHC experiment at the CERN Large Hadron Collider. The analysis uses proton--proton collision data at a centre-of-mass energy of $\sqrt{s}=13.6$ TeV, corresponding to an integrated luminosity of $68.6{\text{fb}}^{-1}$ collected during LHC Run 3 in 2022 and 2023. A total of 31 $\hat{I}{½}_{\hat{I}}¼$ CC candidates are selected against an expected background of $5.0\pm 1.1$ events, consistent with a signal expectation of $24_{-9}^{+10}$ events. The signal strength is measured to be $\hat{\hat{I}}¼=1.09_{-0.37}^{+0.72}$, and the combined muon neutrino and anti-neutrino CC cross section on tungsten is determined to be $\ddot{I}ƒ(\hat{I}{½}_{\hat{I}}¼+\bar{\hat{I}}{½}_{\hat{I}}¼)=(37_{-12}^{+24})\times 10^{-35}{\text{cm}}^2$ at a median energy of $228$ GeV. In addition, a calorimetric measurement of the hadronic energies of the neutrino candidate events is performed, making use of calibration data from dedicated test-beam campaigns.