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Abstract:

This paper reports a measurement by the T2K experiment of the ν μ charged current quasielastic (CCQE) cross section on a carbon target with the off-axis detector based on the observed distribution of muon momentum ( p μ ) and angle with respect to the incident neutrino beam ( θ μ ). The flux-integrated CCQE cross section was measured to be ⟨ σ ⟩ = ( 0.83 ± 0.12 ) × 10 − 38     cm 2 . The energy dependence of the CCQE cross section is also reported. The axial mass, M QE A , of the dipole axial form factor was extracted assuming the Smith-Moniz CCQE model with a relativistic Fermi gas nuclear model. Using the absolute (shape-only) p μ − cos θ μ distribution, the effective M QE A parameter was measured to be 1.2 6 + 0.21 − 0.18     GeV / c 2 ( 1.4 3 + 0.28 − 0.22     GeV / c 2 ).