Precision Mass Measurements of Cd129-131 and Their Impact on Stellar Nucleosynthesis via the Rapid Neutron Capture Process

Abstract

Masses adjacent to the classical waiting-point nuclide Cd-130 have been measured by using the Penningtrap spectrometer ISOLTRAP at ISOLDE/CERN. We find a significant deviation of over 400 keV from earlier values evaluated by using nuclear beta-decay data. The new measurements show the reduction of the N = 82 shell gap below the doubly magic Sn-132. The nucleosynthesis associated with the ejected wind from type-II supernovae as well as from compact object binary mergers is studied, by using state-of-the-art hydrodynamic simulations. We find a consistent and direct impact of the newly measured masses on the calculated abundances in the A = 128-132 region and a reduction of the uncertainties from the precision mass input data.