Charged Pion Production in $\nu_\mu$ Interactions on Hydrocarbon at   $\langle E_{\nu}\rangle$= 4.0 GeV
  Charged pion production via charged current $\nu_{\mu}$ interactions on plastic (CH) is studied using the MINERvA detector exposed to the NuMI wideband neutrino beam at Fermilab. Events with hadronic invariant mass W $<$ 1.4 GeV are selected to isolate single pion production, which is expected to occur primarily through the $\Delta(1232)$ resonance. Cross sections as functions of pion production angle and kinetic energy are reported and compared to predictions from different theoretical calculations and generator-based models, for neutrinos ranging in energy from 1.5 GeV to 10 GeV. The data are best described by calculations which include significant contributions from pion intranuclear rescattering. These measurements constrain the primary interaction rate and the role of final state interactions in pion production, both of which need to be well understood by neutrino oscillation experiments. 
B. Eberly, L. Aliaga, O. Altinok, M.G. Barrios Sazo, L. Bellantoni, M.   Betancourt, A. Bodek, A. Bravar, H. Budd, M. J. Bus...
hep-ex