Relativistic mean-field theory on the xenon, cesium and barium isotopes

We apply the relativistic mean-field theory to unstable nuclei with Z = 54, 55 and 56. We compare the results of calculations to experimental data of the mean-square-charge radii and binding energies using the parameter set, TM1. The constraint calculations results in an energy curve as a function of deformation with several candidates for the absolute minimum for each nucleus. The strong shell effect at N = 82, for the Xe and Ba isotopes is clearly observed in the present theory, but for Cs isotopes the effect is not so drastic, which is in good agreement with experimental observation. The energy minimum at large prolate deformation, which appears at the proton-rich side, can explain the jump of the mean-square-charge radius at N ∼ 64 for the Cs isotopes.