Precision Mass Measurements of 129-131Cd and Their Impact on Stellar Nucleosynthesis via the Rapid Neutron Capture Process

TL;DR

This study presents precise mass measurements of neutron-rich cadmium isotopes near 130Cd, revealing significant deviations from previous data, which impacts models of stellar nucleosynthesis in supernovae and neutron star mergers.

Contribution

It provides the first high-precision mass measurements of 129-131Cd, showing a reduced N=82 shell gap and directly influencing nucleosynthesis simulations.

Findings

Measured masses deviate over 400 keV from previous beta-decay estimates.

Reduced uncertainties improve the accuracy of nucleosynthesis models.

New data impacts abundance predictions in the A=128-132 region.

Abstract

Masses adjacent to the classical waiting-point nuclide 130Cd have been measured by using the Penning- trap 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 132Sn. 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.