We discuss the observed disagreement between the $Q^2$ distributions of neutrino-nucleus quasielastic events, measured by a number of recent experiments, and the predictions of Monte Carlo simulations based on the relativistic Fermi gas model. The results of our analysis suggest that these discrepancies are likely to be ascribable to both the breakdown of the impulse approximation and the limitations of the Fermi gas description. Several issues related to the extraction of the $Q^2$ distributions from the experimental data are also discussed, and new kinematical variables, which would allow for an improved analysis, are proposed.

• Received 4 January 2010

DOI:https://doi.org/10.1103/PhysRevD.82.013002