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Related papers: Neutron-proton pairing in the BCS approach

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We propose new types of density dependent contact pairing interaction which reproduce the pairing gaps in symmetric and neutron matter obtained by a microscopic treatment based on the nucleon-nucleon interaction. These interactions are able…

Nuclear Theory · Physics 2008-11-26 J. Margueron , Hiroyuki Sagawa , Kouichi Hagino

The ground state of a general pairing Hamiltonian for a finite nuclear system is constructed as a product of collective, real, distinct pairs. These are determined sequentially via an iterative variational procedure that resorts to…

Nuclear Theory · Physics 2015-06-05 M. Sambataro

We describe the ground state of the isovector pairing Hamiltonian in self-conjugate nuclei by a product of collective quartets of different structure built from two neutrons and two protons coupled to total isospin T=0. The structure of the…

Nuclear Theory · Physics 2015-06-18 M. Sambataro , N. Sandulescu

We study a mixture of s-bosons and like-nucleon pairs with the standard pairing interaction outside a inert core. Competition between the nucleon-pairs and s-bosons is investigated in this scenario. The robustness of the BCS-BEC coexistence…

Nuclear Theory · Physics 2017-04-20 Lianrong Dai , Feng Pan , Jerry P. Draayer

We show that the Bogoliubov-de Gennes equations for nuclear ground-state wave functions support solutions in which the condensate has a mixture of spin-singlet and spin-triplet pairing. We find that such mixed-spin condensates do not occur…

Nuclear Theory · Physics 2011-07-28 Alexandros Gezerlis , G. F. Bertsch , Y. L. Luo

We discuss the treatment of isovector pairing by an alpha-like quartet condensate which conserves exactly the particle number, the spin and the isospin. The results show that the quartet condensate describes accurately the isovector pairing…

Nuclear Theory · Physics 2011-09-23 N. Sandulescu , J. Dukelsky , D. Negrea

The coupled dynamics of the scissors mode and the isovector giant quadrupole resonance are studied using a generalized Wigner function moments method taking into account pair correlations. Equations of motion for angular momentum,…

Nuclear Theory · Physics 2009-11-13 E. B. Balbutsev , L. A. Malov , P. Schuck , M. Urban , X. Vinyes

It is shown that the neutron-antineutron oscillation per se does not necessarily imply CP violation in an effective local Lorentz invariant description of the neutron which preserves CPT, contrary to a recent analysis in the literature. A…

High Energy Physics - Phenomenology · Physics 2015-10-06 Kazuo Fujikawa , Anca Tureanu

Pseudo-spin symmetry in nuclei is investigated considering the Dirac equation with a Lorentz structured Woods-Saxon potential. The isospin correlation of the energy splittings of pseudo-spin partners with the nuclear potential parameters is…

Nuclear Theory · Physics 2009-11-06 P. Alberto , M. Fiolhais , M. Malheiro , A. Delfino , M. Chiapparini

We study the phase diagram of isospin-asymmetrical nuclear matter in the density-temperature plane, allowing for four competing phases of nuclear matter: (i) the unpaired phase, (ii) the translationally and rotationally symmetric, but…

Nuclear Theory · Physics 2014-12-19 Martin Stein , Armen Sedrakian , Xu-Guang Huang , John W. Clark

We obtain the critical magnetic field required for complete destruction of $S$-wave pairing in neutron matter, thereby setting limits on the pairing and superfluidity of neutrons in the crust and outer core of magnetars. We find that for…

Nuclear Theory · Physics 2016-02-02 Martin Stein , Armen Sedrakian , Xu-Guang Huang , John W. Clark

A survey of pairing properties of nucleonic matter is presented that includes the off-shell propagation associated with short-range and tensor correlations. For this purpose, the gap equation has been solved in its most general form…

Nuclear Theory · Physics 2016-08-16 H. Müther , W. H. Dickhoff

The dineutron correlations and the crossover from superfluidity of neutron Cooper pairs in the $^1S_0$ pairing channel to Bose-Einstein condensation (BEC) of dineutron pairs in both symmetric and neutron matter are studied within the…

Nuclear Theory · Physics 2013-04-24 Bao Yuan Sun , Wei Pan

The mass difference between the even-even isobaric nuclei having the valence nucleons on the same degenerate level is attributed to a Josephson-type interaction between pairs of protons and pairs of neutrons. This interaction can be…

Nuclear Theory · Physics 2009-11-11 M. Grigorescu

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

Isoscalar Cooper pairing in isospin asymmetric nuclear matter occurs between states populating two distinct Fermi surfaces, each for neutrons and protons. The transition from a BCS-like to the normal (unpaired) state, as the isospin…

Nuclear Theory · Physics 2009-11-07 Herbert Müther , Armen Sedrakian

A systematic investigation of the rotating $N=Z$ even-even nuclei in the mass $A=58-80$ region has been performed within the frameworks of the Cranked Relativistic Mean field, Cranked Relativistic Hartree Bogoliubov theories and cranked…

Nuclear Theory · Physics 2009-11-10 A. V. Afanasjev , S. Frauendorf

We perform Hartree-Fock-Bogoliubov (HFB) calculations for semi-magic Calcium, Nickel, Tin and Lead isotopes and $N$=20, 28, 50 and 82 isotones using density-dependent pairing interactions recently derived from a microscopic nucleon-nucleon…

Nuclear Theory · Physics 2008-11-26 J. Margueron , H. Sagawa , K. Hagino

We study two systems of BPS solitons in which spin-spin interactions are important in establishing the force balances which allow static, multi-soliton solutions to exist. Solitons in the Israel-Wilson-Perjes (IWP) spacetimes each carry…

High Energy Physics - Theory · Physics 2009-10-31 David Kastor , Jennie Traschen

The $T$=2 excitations in even-even $N$=$Z$ nuclei are calculated within the isospin cranked mean-field approach. The response of pairing correlations to rotation in isospace is investigated. It is shown that whereas the isovector pairing…

Nuclear Theory · Physics 2009-11-06 W. Satuła , R. Wyss