Study of decay properties for Ba to Nd nuclei relevant for the formation of the r-process rare-earth peak (A similar to 160)

At the RIKEN Nishina Center, exotic neutron-rich isotopes of Ba, La, Ce, Pr, and Nd were measured. This work reports their half-lives (T-1/2) and beta-delayed neutron-emission probabilities (P-xn). The setup consisted of the BigRIPS in-flight separator for particle identification, the Advanced Implantation Detector Array (AIDA) for ions and beta detection, and the BRIKEN neutron counter for neutron detection. Using this arrangement, 4 new T-1/2 and 14 new P1n were measured. Furthermore, 38 T-1/2 and 2 P-1n values were remeasured, decreasing the uncertainties for some of them. In addition to improving predictions of nucleosynthesis models that describe the production of the rare-earth peak at A similar to 160 via the r-process, these additional experimental data should help to constrain theoretical models for calculations of T-1/2 and P-xn in this region.