Beta-Delayed Neutron Emission of N=84 ^{132}Cd

Area of Science:

• Nuclear Physics
• Nuclear Astrophysics
• Computational Physics

Background:

• Understanding beta-delayed neutron emission is crucial for nuclear astrophysics, particularly for r-process nucleosynthesis.
• Accurate theoretical models are needed to predict decay properties of neutron-rich nuclei, which are difficult to measure experimentally.

Purpose of the Study:

• To experimentally measure the beta-delayed neutron emission of Cadmium-132.
• To validate and refine large-scale shell model (LSSM) calculations for predicting nuclear decay properties.
• To compare LSSM predictions with global models like the finite-range droplet model (FRDM).

Main Methods:

• Time-of-flight technique for measuring beta-delayed neutron emission.
• Large-scale shell model (LSSM) calculations utilizing the N³LO interaction.
• Comparison of calculated beta-decay half-lives and neutron branching ratios with experimental data and other theoretical models.

Main Results:

• Experimental data for beta-delayed neutron emission of Cadmium-132 were obtained.
• LSSM calculations accurately reproduced known half-lives and neutron branching ratios.
• The study suggests that a neutron in the g_{7/2} orbital transforms into a proton in the g_{9/2} orbital, driving the decay.

Conclusions:

• The presented LSSM, validated by Cadmium-132 data, provides robust predictions for nuclear decay properties.
• Current leading global models may overestimate half-lives for nuclei with Z<50 and N≥82.
• The model has significant predictive power for nuclei relevant to the r-process, including waiting points.