First measurement of the cross section for νμ and ν μ induced single charged pion production on argon using

We report on the first cross section measurement of charged-current single charged pion production by neutrinos and antineutrinos on argon. This analysis was performed using the ArgoNeuT detector exposed to the NuMI beam at Fermilab. The measurements are presented as functions of muon momentum, muon angle, pion angle, and angle between muon and pion. The flux-averaged cross sections are measured to be 2.7±0.5(stat)±0.5(syst)×10-37 cm2/Ar for neutrinos at a mean energy of 9.6 GeV and 8.4±0.9(stat)-0.8+1.0(syst)×10-38 cm2/Ar for antineutrinos at a mean energy of 3.6 GeV with the charged pion momentum above 100 MeV/c. The results are compared with several model predictions.