Exact isovector pairing in a shell-model framework: Role of proton-neutron correlations in isobaric analog states

Miora, M. E.; Launey, K. D.; Kekejian, D.; Pan, F.; Draayer, J. P.

doi:10.1103/physrevc.100.064310

Title: Exact isovector pairing in a shell-model framework: Role of proton-neutron correlations in isobaric analog states

Journal Article · 12 December 2019 · Physical Review. C

DOI: https://doi.org/10.1103/physrevc.100.064310 · OSTI ID:1801969

Miora, M. E. ^[1];

^[2]; Kekejian, D. ^[2]; Pan, F. ^[3]; Draayer, J. P. ^[2]

Rollins College, Winter Park, FL (United States); Louisiana State Univ., Baton Rouge, LA (United States); OSTI
Louisiana State Univ., Baton Rouge, LA (United States)
Louisiana State Univ., Baton Rouge, LA (United States); Liaoning Normal University, Dalian (China)

Here, we utilize a nuclear shell model Hamiltonian with only two adjustable parameters to generate, for the first time, exact solutions for pairing correlations for light to medium-mass nuclei, including the challenging proton-neutron pairs, while also identifying the primary physics involved. In addition to single-particle energy and Coulomb potential terms, the shell model Hamiltonian consists of an isovector T = 1 pairing interaction and an average proton-neutron isoscalar T = 0 interaction, where the T = 0 term describes the average interaction between nonpaired protons and neutrons. This Hamiltonian is exactly solvable, where, utilizing three to seven single-particle energy levels, we reproduce experimental data for 0⁺ state energies for isotopes with mass A = 10 through A = 62 exceptionally well including isotopes from He to Ge. Additionally, we isolate effects due to like-particle and proton-neutron pairing, provide estimates for the total and proton-neutron pairing gaps, and reproduce N (neutron) = Z (proton) irregularity. These results provide a further understanding for the key role of proton-neutron pairing correlations in nuclei, which is especially important for waiting-point nuclei on the $$\mathcal{rp}$$ path of nucleosynthesis.

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Research Organization:: Texas A & M Univ., Commerce, TX (United States)

Sponsoring Organization:: USDOE Office of Science (SC); National Science Foundation (NSF); National Natural Science Foundation of China (NSFC); State of Illinois

Grant/Contract Number:: SC0009971

OSTI ID:: 1801969

Journal Information:: Physical Review. C, Journal Name: Physical Review. C Journal Issue: 6 Vol. 100; ISSN 2469-9985

Publisher:: American Physical Society (APS)Copyright Statement

Country of Publication:: United States

Language:: English

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