2025/07/19 by Yu, Y. X., Chen, Q. Y., Qi, Chong +1
#FOS: Physical sciences #Nuclear Theory (nucl-th)
paper · doi:10.48550/arxiv.2507.14506
In this work, we present a systematic study of low-lying states and electromagnetic properties of the semi-magic N = 82 isotonic chain with proton number Z=51-77, using the full configuration interaction shell model with a newly developed high-quality effective interaction. The calculations are performed in a large model space that includes all proton orbitals between Z = 50 and 82: 0g7/2, 1d5/2, 1d3/2, 2s1/2, and 0h11/2. The effective interaction is derived through the principal component analysis approach, starting from 160 two-body matrix elements and 5 single-particle energies and considering up to 30 degrees of freedom. Those are optimized by fitting to 204 available experimental energy levels. The resulting root-mean-square deviation is as low as 102 keV. The new interaction successfully reproduces the binding energies, low-lying spectra, electric quadrupole transition probabilities B(E2), and magnetic dipole moments across both even-even and odd-mass isotones, with consistent agreement with experimental values. The nuclear structure of low-lying states is analyzed in detail. Additionally, predictions are made for several more proton-rich nuclei beyond current experimental reach, including 155Ta, 156W, 157Re, 158Os, and 159Ir.