We have isolated muon anti-neutrino charged-current quasi-elastic interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cr
oss-section, d{sigma}/dQ^2, and compare to several theoretical models of quasi-elastic scattering. Good agreement is obtained with a model where the nucleon axial mass, M_A, is set to 0.99 GeV/c^2 but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross-section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q^2 favor this interpretation over an alternative in which the axial mass is increased.
The next generation of neutrino oscillation experiments aims to answer many interesting questions, such as whether there is CP violation in the neutrino sector and whether sterile neutrinos exist. These experiments will require high precision cross s
ection measurements of various neutrino and anti-neutrino interaction channels. We review results and prospects for such measurements from the MiniBooNE, T2K, MINER$ u$A and ArgoNeuT collaborations.
