Narrow Results

The ground state properties namely the binding energy, the root mean square (rms) radius (neutron, proton and charge) and the deformation parameter of 45 newly identified neutron-rich isotopes in the A~71–152 mass region have been predicted in the relativistic mean filed (RMF) framework along with the Bardeen–Cooper–Schrieffer (BCS) type of pairing. Validity of the RMF results with the NL3 effective force are tested for odd-A Zn and Rh isotopic chains without taking the time reversal symmetry breaking effects into consideration. The RMF prediction on the binding energies are in good agreement with the empirical/finite-range droplet model calculation. The shell effects on the rms radii of odd-A Zn and Rh isotopes are nicely reproduced. The possibility of shape-coexistence in the newly identified nuclei is discussed.

The method of proton elastic scattering at intermediate energies, which was already proven for neutron-rich helium isotopes to be well suited for obtaining accurate and detailed information on nuclear matter distributions of halo nuclei, was recently applied for investigation of neutron-rich Li-isotopes using secondary beams from the Fragment Separator at GSI at an energy near 700 MeV/u. Along with the radioactive ^8,9,11Li isotopes, the stable ⁶Li nucleus was investigated to allow for a comparison of the matter distributions between the A = 6 nuclei ⁶Li and ⁶He. The experimental setup consisted of the ionization chamber IKAR which served simultaneously as a high-pressure hydrogen target and as a recoil proton detector, and a forward spectrometer for tracking and identifying the projectile nuclei.

For determining the nuclear matter distributions the measured differential cross-sections have been compared to those calculated in the frame of the Glauber multiple scattering theory using various parametrizations for the nucleon density distributions as input. The results on the nuclear matter radii and the matter distributions are presented. The nuclear matter distribution deduced for the ¹¹Li nucleus exhibits a very pronounced halo structure. The present data allow also for a sensitive test of theoretical model calculations on the structure of the neutron-rich nuclei. A few examples are given.

The progress in experimental research on the octupole correlations in neutronrich even-even Ce isotopes by our collaboration has been reviewed. The experiments were carried out by measuring the prompt γ-rays in the spontaneous fission of ²⁵²Cf. The octupole correlations with s = +1 band structure in ^{144, 146, 148, 152}Ce were identified or expanded. The s = ± 1 double octuple band structure in ¹⁴⁸Ce was discovered. Systematic characteristics of the octupole correlations in these even-even Ce isotopes have been discussed.