Speaker
Description
The neutron-rich $N \sim 126$ region is important to r-process calculations, but difficult to be accessed by experiments. This region is unique for its strong competition between allowed and first-forbidden transitions, which complicates half-life predictions. Besides, the abundances of the third r-process peak elements and actinides are sensitive to half-lives of $N = 126$ isotones. Measurements of more exotic nuclei are essential to benchmark theoretical models commonly used in r-process calculations. We will present results from the BRIKEN experiment, which is the first attempt to investigate $N \sim 126$ nuclei at RIBF. Particle identification was confirmed by the BigRIPS separator and a silicon energy-loss telescope. Charged-particle decay and neutron emission were measured by the WAS3ABi beta-counting system and the BRIKEN neutron counter. Half-lives and beta-delayed neutron emission probabilities ($P_n$) of $N \sim 126$ exotic isotopes were determined. Several of which were first measurements. Preliminary results of $Z \leqq 79$ isotopes will be discussed.
