  Semi-inclusive $CC\nu$ cross sections based on factorized cross sections are
studied for a selection of spectral function models with the objective of
facilitating the choice of models for use as input into event generators. The
basic formalism for such cross sections is presented along with an introduction
to constructing spectral functions for simple models based on the independent
particle shell model (IPSM), the relativistic Fermi gas model (RFG) and a local
density approximation (LDA) based on the RFG. Spectral functions for these
models are shown for $^{16}$O along with a more sophisticated model which
includes nucleon-nucleon interactions \cite{ALVAREZRUSO20181}. Inclusive and
semi-inclusive cross sections are calculated for these models. Although the
inclusive cross sections are all of similar size and shape, the semi-inclusive
cross sections are subtantially different depending upon whether the spectral
functions contain some features associated with the nuclear shell model or are
based on the RFG and LDA models. Calculations of average values and standard
deviations of the initial neutrino energy using the semi-inclusive cross
section for the various models are presented and indicate that there may be
simple kinematical descriptions of the average neutrino energy which is common
to all of these models.
