Intertwined effects of pairing and deformation on neutron halos in magnesium isotopes

Abstract

Matter radii of the ${}^{34-40}$Mg nuclei are investigated by self-consistent Hartree-Fock-Bogolyubov calculations assuming the axial symmetry. With the semi-realistic M3Y-P6 interaction, the $N$-dependence of the matter radii observed in the experiments is reproduced excellently. Both the pairing and the deformation play significant roles in an intertwined manner. The ${}^{35}$Mg nucleus has a smaller radius than the neighboring even-$N$ nuclei, which is attributed to its smaller deformation. In contrast, a neutron halo is obtained in ${}^{37}$Mg. We point out that, in contrast to the pairing anti-halo effect that may operate on the even-$N$ nuclei, the pair correlation enhances halos in odd-$N$ nuclei, owing to the new mechanism which we call \textit{unpaired-particle haloing}. The halo in ${}^{37}$Mg is predicted to have peanut shape in its intrinsic state, reflecting $p$-wave contribution, as in ${}^{40}$Mg. The $N$-dependence of the deformation is significant again, by which the single-particle level dominated by the $p$-wave component comes down.

arXiv comment5 pages including 2 figures, to be published in PRC (Rapid Communication)

References in corpus (23)

• Relativistic Continuum Hartree Bogoliubov Theory for Ground State Properties of Exotic Nuclei
• Neutron halo in deformed nuclei
• Correlations beyond the mean field in Magnesium isotopes: Angular momentum projection and configuration mixing
• Halos in medium-heavy and heavy nuclei with covariant density functional theory in continuum
• Microscopic justification of the Equal Filling approximation
• Deformed relativistic Hartree Bogoliubov theory in continuum
• One-quasiparticle States in the Nuclear Energy Density Functional Theory
• Hartree-Fock approach to nuclear matter and finite nuclei with M3Y-type nucleon-nucleon interactions
• Pairing anti-halo effect
• Deformed nuclear halos
• Ground-state properties of neutron-rich Mg isotopes
• Nilsson diagrams for light neutron-rich nuclei with weakly-bound neutrons
• Tensor-force effects on single-particle levels and proton bubble structure around the $Z$ or $N=20$ magic number
• Semi-realistic nucleon-nucleon interactions with improved neutron-matter properties
• A method of implementing Hartree-Fock calculations with zero- and finite-range interactions
• Application of Gaussian expansion method to nuclear mean-field calculations with deformation
• Predicting magic numbers of nuclei with semi-realistic nucleon-nucleon interactions
• Hartree-Fock-Bogolyubov calculations with Gaussian expansion method
• Ground-state properties of even and odd Magnesium isotopes in a symmetry-conserving approach
• Role of deformation in odd-even staggering in reaction cross sections for ${}^{30,31,32}$Ne and ${}^{36,37,38}$Mg isotopes
• Ground-state properties and symmetry energy of neutron-rich and neutron-deficient Mg isotopes
• RPA calculations with Gaussian expansion method
• Influence of pairing correlations on the radius of neutron-rich nuclei

Cited by in corpus (17)

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• Study of ground state properties of carbon isotopes with deformed relativistic Hartree-Bogoliubov theory in continuum
• Deformed relativistic Hartree-Bogoliubov theory in continuum with a point-coupling functional. II. Examples of odd Nd isotopes
• Rotating deformed halo nuclei and shape decoupling effects
• Missed prediction of the neutron halo in ${}^{37}$Mg
• Angular momentum projection in the deformed relativistic Hartree-Bogoliubov theory in continuum
• Hartree-Fock-Bogoliubov theory for odd-mass nuclei with a time-odd constraint and application to deformed halo nuclei
• Shape evolution of Zr nuclei and roles of tensor force
• Properties of exotic nuclei and their linkage to the nucleonic interaction
• Role of triaxiality in deformed halo nuclei
• Prediction of two-neutron halos in the $N=28$ isotones ${}^{40}$Mg and ${}^{39}$Na
• Weak binding effects on the structure of ${}^{40}$Mg
• Collapse of N$=$28 magicity in exotic ${}^{40}$Mg -- Probe of deformed halo and 2n-radioactivity at Mg neutron drip-line
• Analysis of Peierls-Yoccoz rotational energy of nuclei with semi-realistic interaction
• Deformation, halo, and bubble structure: A paradigm shift of exotic phenomena in light to medium mass nuclei
• Models for Pairing Phenomena
• Pairing effects on pure rotational energy of nuclei