Muon spectra of quasi-elastic and 1-pion production events in LBL neutrino oscillation experiments

Abstract The muon energy spectra of the quasi-elastic and 1-pion production events in a LBL experiment, like K2K, are predicted to follow closely the neutrino energy spectrum, with downward shifts of the energy scale by 〈 Q 2 〉/2 M and (〈 Q 2 〉+ M Δ 2 − M 2 )/2 M , respectively. These predictions seem to agree with the observed muon spectra in the K2K nearby detector. The corresponding muon spectra in the far-away (SK) detector are predicted to show characteristic spectral distortions induced by ν μ oscillation. Comparison of the predicted spectral distortions with the observed muon spectra of the 1-ring and 2-ring muon events in the SK detector will help to determine the oscillation parameters. The results will be applicable to other LBL experiments as well.