  The MiniBooNE experiment has collected what is currently the world's largest
sample of neutrino muon charged current single charged pion interactions,
roughly 46,000 events. The purity of the CC1pi+ sample is 87% making this the
purest event sample observed in the MiniBooNE detector. The average energy of
neutrinos producing CC1pi+ interactions in MiniBooNE is about 1 GeV, therefore
the study of these events can provide insight into both resonant and coherent
pion production processes. In this talk, we will discuss the long-standing
discrepancy in four-momentum transfer observed between CC1pi+ data and existing
predictions. Several attempts to address this problem will be presented.
Specifically, the Rein-Sehgal model has been extended to include muon mass
terms for both resonant [Kuzmin et al. and Berger and Sehgal] and coherent
production. Using calculations from Graczyk and Sobczyk paper, an updated form
for the vector form factor [Lalakulich et al.] has also been adopted. The
results of this improved description of CC1pi+ production will be compared to
the high statistics MiniBooNE CC1pi+ data and several existing parametrisations
of the axial vector form factor.
