Four-nucleon alpha-type correlations and proton-neutron pairing away of N=Z line

Abstract

We study the competition between alpha-type and conventional pair condensation in the ground state of nuclei with neutrons and protons interacting via a charge-independent pairing interaction. The ground state is described by a product of two condensates, one of alpha-like quartets and the other one of pairs in excess relative to the isotope with N=Z. It is shown that this ansatz for the ground state gives very accurate pairing correlation energies for nuclei with the valence nucleons above the closed cores 16O, 40Ca and 100Sn. These results indicate that alpha-type correlations are important not only for the self-conjugate nuclei but also for nuclei away of N=Z line. In the latter case alpha-like quartets coexist with the collective Cooper pairs formed by the nucleons in excess.

10 pages, 4 tables

References in corpus (4)

• Alpha-like quartet condensation and isovector pairing correlations in N=Z nuclei
• Accuracy of BCS-based approximations for pairing in small Fermi systems
• Isovector neutron-proton pairing with particle number projected BCS
• Pairing theory of the symmetry energy

Cited by in corpus (25)

• Isoscalar and isovector pairing in a formalism of quartets
• No-core configuration-interaction model for the isospin- and angular-momentum-projected states
• Four-body correlations in nuclei
• Isovector proton-neutron pairing and Wigner energy in Hartree-Fock mean field calculations
• Isovector pairing in a formalism of quartets for N=Z nuclei
• A quartet BCS-like theory
• Deformation effects on the coexistence between neutron-proton and particle like pairing in N=Z medium mass nuclei
• Isoscalar-isovector proton-neutron pairing and quartet condensation in N=Z nuclei
• Quartet correlations in N=Z nuclei induced by realistic two-body interactions
• Treatment of like-particle pairing with quartets
• Isovector and isoscalar proton-neutron pairing in $N>Z$ nuclei
• Isospin effects in N~Z nuclei in extended Density Functional Theory
• Quartetting in odd-odd self-conjugate nuclei
• Bridging the quartet and pair pictures of isovector proton-neutron pairing
• $\alpha$-like quartetting in the excited states of proton-neutron pairing Hamiltonians
• Analytical approach for the Quartet Condensation Model
• The $\beta$-decay properties of $N=Z$ nuclei: Role of neutron-proton pairing and the shell model interpretation
• Disentangling the pair and quartet condensates
• Exact T=0 Eigenstates of the Isovector Pairing Hamiltonian
• Unified description of pairing and quarteting correlations within the particle-hole-boson approach
• Collective treatment of the isovector pair correlations. Boson representation
• Isovector pair correlations in analytically solvable models
• Coexistence of quartets and pairs in even-even $N>Z$ nuclei
• Structure of the quartetting ground state of $N=Z$ nuclei
• Collective model with isovector pair and alpha-particle type correlations