Precision Mass Measurements of Neutron-Rich Neodymium and Samarium Isotopes and Their Role in Understanding Rare-Earth Peak Formation

R. Orford et al.

PRL 120, 262702 (2018)

The Canadian Penning Trap mass spectrometer at CARIBU was used to measure the masses of eight neutron-rich isotopes of Nd and Sm. These measurements are the first to push into the region of nuclear masses relevant to the formation of the rare-earth abundance peak at A$\sim$165 by the rapid neutron-capture process. We compare our results with theoretical predictions obtained from ``reverse-engineering'' the mass surface that best reproduces the observed solar abundances in this region through a Markov Chain Monte Carlo technique. Our measured masses are consistent with the reverse-engineering predictions for a neutron star merger wind scenario.