Probing neutron-rich nuclei along the dripline with PYXIS

Since 2023, several cohorts of the Physicists Inspiring the Next Generation: Exploring the Nuclear Matter (PING) program at the Facility for Rare Isotope Beams (FRIB) have included pre-college and undergrad students to develop a novel neutron detector, PYXIS, to complement the MoNA-LISA array of the MoNA Collaboration. PYXIS was placed beside MoNA-LISA during the first two experiments of the Collaboration conducted in the summer 2025 .

The PING cohorts, going back to its implementation, formed various groups to address the science enabled by PYXIS ranging from simulation, data analysis and theory. For the latter, a Python script was developed to calculate the relativistic kinematics of neutron decay . This allows for the theoretical predictions of the distribution of excitation energies to be compared with the experimental data. Statistical and visual tools such as histograms and heatmaps were used to interpret the context of such nuclear structure models. Additionally, the code tracks event frequency and provides the likelihood of decay across the excitation spectrum. These findings contribute to generating predictive distributions of data collected from MoNA and PYXIS as well as simulating decay behavior and structure near the neutron drip line. A review of the theory work performed will be presented and discussed.