Construction of spectral functions for medium nuclei

This article is aimed at improving the description of lepton-nucleus interactions in the sub-GeV energy range. Approximate spectral functions for oxygen, calcium, and argon are constructed and used to obtain the electron cross sections in a given scattering angle. Comparison with a sample of available experimental data shows satisfactory agreement. Discrepancy between the presented model and the systematic computations available for oxygen [O. Benhar et al., Phys. Rev. D 72, 053005 (2005)] is also found to be very small. Analysis of appropriate kinematical regions leads to the conclusion that the obtained argon spectral function should describe well neutrino scattering in the 800-MeV energy region. Several approximations used in the model are critically reviewed. All the details needed to implement the presented approach in Monte Carlo simulations are given.