A Liquid Drop Model (LDM) for Nuclear Semi-Bubbles or, more Generally, Systems Consisting of Domains with Different Constant Density

For hyperheavy nuclei with proton-numbers Z in the interval 160 ⪝ Z ⪝ 230 and corresponding neutron numbers N in the interval 300 ⪝ N ⪝ 500, the density distribution of nucleons exhibits a central depression according to HFB-calculations performed with the Gogny interaction [1]. The physical reason for this phenomenon is the fact that for these large charge numbers the gain in binding energy by the reduction of the Coulomb energy is larger than the loss of nuclear binding energy as a result of the central density reduction.