One-body density matrix and momentum distribution ins−pands−dshell nuclei

Abstract

Analytical expressions of the one- and two-body terms in the cluster expansion of the one-body density matrix and momentum distribution of the $s\ensuremath{-}p$ and $s\ensuremath{-}d$ shell nuclei with $N=Z$ are derived. They depend on the harmonic oscillator parameter b and the parameter $\ensuremath{\beta}$ which originates from the Jastrow correlation function. These parameters have been determined by least squares fit to the experimental charge form factors. The inclusion of short-range correlations increases the high momentum component of the momentum distribution $n(\mathbf{k})$ for all nuclei we have considered while there is an A dependence of $n(\mathbf{k})$ both at small values of k and the high momentum component. The A dependence of the high momentum component of $n(\mathbf{k})$ becomes quite small when the nuclei ${}^{24}\mathrm{Mg},$ ${}^{28}\mathrm{Si},$ and ${}^{32}\mathrm{S}$ are treated as $1d\ensuremath{-}2s$ shell nuclei having the occupation probability of the $2s$ state as an extra free parameter in the fit to the form factors.