We suggest that the number of correlated nucleon pairs in an arbitrary nucleus can be estimated by counting the number of proton-neutron, proton-proton, and neutron-neutron pairs residing in a relative $S$ state. We present numerical calculations of those amounts for the nuclei ${}^4$He, ${}^9$Be, ${}^{12}$C, ${}^{27}$Al, ${}^{40}$Ca, ${}^{48}$Ca, ${}^{56}$Fe, ${}^{63}$Cu, ${}^{108}$Ag, and ${}^{197}$Au. The results are used to predict the values of the ratios of the per-nucleon electron-nucleus inelastic scattering cross section to the deuteron in the kinematic regime where correlations dominate.

• Received 5 May 2011

DOI:https://doi.org/10.1103/PhysRevC.84.031302