Matter density distributions of Ne20,22 and Mg24,26

Reported small-angle differential cross sections of proton elastic scattering off $^{20,22}\mathrm{Ne}$ and $^{24,26}\mathrm{Mg}$ at 0.8 GeV were analyzed with the Glauber model. Matter density distributions of $^{20,22}\mathrm{Ne}$ and $^{24,26}\mathrm{Mg}$ were determined based on the two-parameter Fermi density model, and the corresponding root-mean-square point-matter radii are 2.891(52) fm, 2.895(104) fm, 2.935(20) fm, and 2.946(21) fm. The occupation number effects of the $2s$ orbital on inner density were probed by the matter density difference between $^{22}\mathrm{Ne}$ and $^{24}\mathrm{Mg}$. Combined with the experimental occupation numbers, the relativistic Hartree-Bogoliubov calculations with the DD-ME2 and PC-PK1 interactions describe the obtained density difference trend, and indicate that there may be a bubble structure in $^{24}\mathrm{Mg}$.