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

Half-lifes ( T 1/2 ) of exotic neutron-rich isotopes of Ba, La, Ce, Pr, and Nd were measured at the RIKEN Nishina Center. The experimental setup consisted of the BigRIPS in-flight separator for ion selection identification, the Advance Implantation Detector Array (AIDA) for ions and β detection, and the BRIKEN detector for neutron counting. Using this setup, 4 new T 1/2 have been measured for the first time, and 38 T 1/2 have been remeasured with improved precision in several cases. These new experimental data should help to constrain theoretical models for calculations of T 1/2 . The status of the experimental analysis and preliminary results are provided in this contribution.