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arXiv · 2106.12128

Quadrupole moments and proton-neutron structure in p-shell mirror nuclei

M. A. Caprio·P. J. Fasano·P. Maris·A. E. McCoy
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Abstract

Electric quadrupole (E2) matrix elements provide a measure of nuclear deformation and related collective structure. Ground-state quadrupole moments in particular are known to high precision in many p-shell nuclei. While the experimental electric quadrupole moment only measures the proton distribution, both proton and neutron quadrupole moments are needed to probe proton-neutron asymmetry in the nuclear deformation. We seek insight into the relation between these moments through the ab initio no-core configuration interaction (NCCI), or no-core shell model (NCSM), approach. Converged ab initio calculations for quadrupole moments are particularly challenging, due to sensitivity to long-range behavior of the wave functions. We therefore study more robustly-converged ratios of quadrupole moments: across mirror nuclides, or of proton and neutron quadrupole moments within the same nuclide. In calculations for mirror pairs in the p shell, we explore how well the predictions for mirror quadrupole moments agree with experiment and how well isospin (mirror) symmetry holds for quadrupole moments across a mirror pair.

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M. A. Caprio, P. J. Fasano, P. Maris, A. E. McCoy. 2021-09-18. Quadrupole moments and proton-neutron structure in p-shell mirror nuclei. https://doi.org/10.1103/physrevc.104.034319

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