Measuring the ?-decay Properties of Neutron-rich Exotic Pm, Sm, Eu, and Gd Isotopes to Constrain the Nucleosynthesis Yields in the Rare-earth Region

Abstract The ? -delayed neutron-emission probabilities of 28 exotic neutron-rich isotopes Pm, Sm, Eu, and Gd were measured for the first time at RIKEN Nishina Center using Advanced Implantation Detector Array (AIDA) BRIKEN neutron detector array. existing -decay half-life ( T 1/2 ) database was significantly increased toward more isotopes, uncertainties previously values decreased. new data not only constrain theoretical predictions half-lives probabilities, but also allow probing mechanisms formation high-mass wing rare-earth peak located A ? 160 in r -process abundance distribution through astrophysical reaction network calculations. An uncertainty quantification calculated patterns with shows a reduction region. newly introduced variance-based sensitivity analysis method offers valuable insight into influence important nuclear physics inputs on patterns. has identified 168 Sm several gadolinium as some key variables among current experimental to understand remaining = 167–172.