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Related papers: Proton-neutron pairing correlations in the nuclear…

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Unlike their lighter counterparts, most odd-odd N=Z nuclei with mass A > 40 40 have ground states with isospin T=1, suggesting an increased role for the isovector pairing interaction. A simple SO(5) seniority-like model of this interaction…

Nuclear Theory · Physics 2008-11-26 J. Engel , K. Langanke , P. Vogel

We examine isovector and isoscalar proton-neutron pairing correlations for the ground state of even-even Ge isotopes with mass number A=64-76 within the deformed BCS approach. For N=Z 64Ge the BCS solution with only T=0 proton-neutron pairs…

Nuclear Theory · Physics 2009-11-10 Fedor Simkovic , Charal Moustakidis , Larisa Pacearescu , Amand Faessler

A study is carried out of the role of the aligned neutron-proton pair with angular momentum J=9 and isospin T=0 in the low-energy spectroscopy of the $N=Z$ nuclei $^{96}$Cd, $^{94}$Ag, and $^{92}$Pd. Shell-model wave functions resulting…

Nuclear Experiment · Physics 2011-07-04 S. Zerguine , P. Van Isacker

We perform Shell Model Monte Carlo calculations to study pair correlations in the ground states of $N=Z$ nuclei with masses A=48-60. We find that $T=1$, $J^{\pi}=0^+$ proton-neutron correlations play an important, and even dominant role, in…

Nuclear Theory · Physics 2009-10-30 K. Langanke , D. J. Dean , S. E. Koonin , P. B. Radha

The role of neutron-proton pairing correlations on the structure of nuclei along the $N=Z$ line is reviewed. Particular emphasis is placed on the competition between isovector ($T=1$) and isoscalar $(T=0$) pair fields. The expected…

Nuclear Theory · Physics 2014-09-19 Stefan Frauendorf , Augusto O. Macchiavelli

We present an analysis of two-proton shell gaps in Sn isotopes. As the theoretical tool we use self-consistent mean-field models, namely the relativistic mean-field model and the Skyrme-Hartree-Fock approach, both with two different pairing…

A review is given of attempts to describe nuclear properties in terms of neutron--proton pairs that are subsequently replaced by bosons. Some of the standard approaches with low-spin pairs are recalled but the emphasis is on a recently…

Nuclear Theory · Physics 2015-06-17 P. Van Isacker

Background: The interacting boson model (IBM) has been used extensively to calculate the matrix elements governing neutrinoless double-beta decay. Studies within other models indicate that a good description of neutron-proton pairing is…

Nuclear Theory · Physics 2017-12-13 P. Van Isacker , J. Engel , K. Nomura

The spin magnetic dipole transitions and the neutron-proton spin-spin correlations in $sd-$shell even-even nuclei with $N=Z$ are investigated using shell model wave functions. The isoscalar spin-triplet pairing correlation provides a…

Nuclear Theory · Physics 2016-11-23 H. Sagawa , T. Suzuki , M. Sasano

The neutron-neutron and proton-proton pairing correlations have long been recognised to be the dominant many-body correlation beyond the nuclear mean field since the introduction of pairing mechanism by Bohr, Mottelson and Pines nearly 60…

Nuclear Theory · Physics 2016-03-28 Chong Qi , R. Wyss

One of the common methods used to investigate the nuclear structures of atomic nuclei is the nuclear shell model. Similar to the placement of atomic electrons into orbits, in the nuclear shell model, protons and neutrons are thought to fill…

Nuclear Theory · Physics 2020-04-14 Serkan Akkoyun , Tuncay Bayram

The influence of the isoscalar and isovector L=0 pairing components of the effective nucleon-nucleon interaction is evaluated for several isobaric chains, in the framework of full pf shell model calculations. We show that the combined…

Nuclear Theory · Physics 2009-10-31 Alfredo Poves , Gabriel Martinez-Pinedo

We report on the development of a new shell-model Monte Carlo algorithm which uses the proton-neutron formalism. Shell model Monte Carlo methods, within the isospin formulation, have been successfully used in large-scale shell-model…

Nuclear Theory · Physics 2015-06-26 C. Ozen , D. J. Dean

A simple model based on the group SO(5) suggests that both the like-particle and neutron-proton components of isovector pairing correlations in odd-A nuclei are Pauli blocked. The same effect emerges from Monte Carlo Shell-model…

Nuclear Theory · Physics 2009-10-31 Jonathan Engel , Karlheinz Langanke , Petr Vogel

Analysis of various mass relations connected with neutron-proton correlations in atomic nuclei is carried out. On the example of $N = Z$ chain it is shown that for self-adjoint nuclei various formulas proposed in literature for $ np $…

Nuclear Theory · Physics 2023-12-11 B. S. Ishkhanov , S. Sidorov , T. Tretyakova , E. Vladimirova

A fermion realization of the compact symplectic sp(4) algebra provides a natural framework for studying isovector pairing correlations in nuclei. While these correlations manifest themselves most clearly in the binding energies of 0^+…

Nuclear Theory · Physics 2008-11-26 K. D. Sviratcheva , A. I. Georgieva , J. P. Draayer

Evolution of quadrupole deformations in $sd$ and $pf$ shell nuclei with mass A= 18$\sim$56 is studied by using deformed Skyrme Hartree-Fock (HF) model with pairing correlations. We point out that the quadrupole deformations of the nuclei…

Nuclear Theory · Physics 2009-11-11 H. Sagawa , X. R. Zhou , X. Z. Zhang

We compute the proton-neutron entanglement entropy in the interacting nuclear shell model for a variety of nuclides and interactions. Some results make intuitive sense, for example that the shell structure, as governed by single-particle…

Nuclear Theory · Physics 2023-03-20 Calvin W. Johnson , Oliver C. Gorton

We treat proton-neutron pairing amplitudes, in addition to the nuclear deformation, as generator coordinates in a calculation of the neutrinoless double-beta decay of 76Ge. We work in two oscillator shells, with a Hamiltonian that includes…

Nuclear Theory · Physics 2014-09-11 Nobuo Hinohara , Jonathan Engel

The evolution of nuclear shell structure is investigated for the first time within density-dependent relativistic Hartree-Fock theory and the role of $\pi$-exchange potential is studied in detail. The energy differences between the neutron…

Nuclear Theory · Physics 2008-11-26 Wen Hui Long , Hiroyuki Sagawa , Jie Meng , Nguyen Van Giai