<i>N</i>and<i>Z</i>dependence of nuclear charge radii

Abstract

This paper is devoted to the analysis of the general trends in the nucleon number dependence of the experimental root-mean-square (rms) charge radii. It is based on the data obtained by different methods of combined treatment of (i) radii changes determined from optical and—to a lesser extent—Kαx-ray isotope shifts, and (ii) absolute radii measured from muonic and electronic scattering experiments. These methods have recently been developed and now updated including experimental data up to the beginning of 2008. Thus, new sets of rms nuclear radii have been obtained covering 865 isotopes for 76 elements from 1H to 96Cm. New information on the isotopic and isotonic behaviour of the nuclear charge radius is obtained with a high accuracy compared to that of the directly measured radii values for the same element. Of special interest is that concerning the light elements and the appearance of non-traditional magic neutron and proton numbers, as N = 6, 14 and Z = 14; the double-magic properties of 96Zr are discussed in more detail. A quantitative criterion is introduced, which points to the peculiarities in the radii trend and offers an opportunity to investigate it more closely. The results provide important information which may serve as a guide to incorporate essential new features into the theoretical approaches.