The merging of the islands of inversion at N=20 and N=28

Abstract

The N=20 and N=28 "islands of inversion" are described by large scale shell model calculations with an extension of the interaction sdpf-u that makes it possible to mix configurations with different Nhw or equivalently with different number of particles promoted from the sd-shell to the pf-shell. It allows to connect the classical sd-shell calculations below N=18 with the sd(protons)-pf(neutrons) calculations beyond N=24-26, for all the isotopes from Oxygen to Calcium, using the same interaction. For some isotopes this range contains all the nuclei between the proton and the neutron drip lines and includes the N=20 and N=28 islands of inversion. We shall pay particular attention to the properties of the states at fix Nhw which turn out to be the real protagonists of the physics at N=20. The existence of islands of inversion/deformation will be explained as the result of the competition between the spherical mean field which favors the 0hw configurations and the nuclear correlations which favor the deformed Nhw configurations. The Magnesium chain is exceptional because in it, the N=20 and N=28 "islands of inversion" merge, enclosing all the isotopes between N=19 and N=30. Indeed, this would be also the case for the Neon and Sodium chains if their drip lines would reach N=28.

10 pages, 14 figures, Minor modifications, new results added

References in corpus (11)

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• Shape transitions in exotic Si and S isotopes and tensor-force-driven Jahn-Teller effect
• A new effective interaction for $0\hslash \omega$ shell model calculations in the sdpf valence space
• Discovery of the shape coexisting 0+ state in 32Mg by a two neutron transfer reaction
• Well-developed deformation in 42Si
• Spectroscopy of 32Ne and the Island of Inversion
• Unveiling the intruder deformed 0${}_2^{+}$ state in ${}^{34}$Si
• Shell structure at N=28 near the dripline: spectroscopy of ${}^{42}$Si, ${}^{43}$P and ${}^{44}$S
• Evolution of the $E(1/2_1^{+})-E(3/2_1^{+})$ energy spacing in odd-mass K, Cl and P isotopes for $N=20-28$
• Measurement of excited states in 40Si and evidence for weakening of the N=28 shell gap
• Exploring the "Island of Inversion" by in-beam gamma-ray spectroscopy of the neutron-rich sodium isotopes 31,32,33Na

Cited by in corpus (62)

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• Ab initio multi-shell valence-space Hamiltonians and the island of inversion
• Exotic neutron-rich medium-mass nuclei with realistic nuclear forces
• The Neutron-Rich Edge of the Nuclear Landscape. Experiment and Theory
• A two-neutron halo is unveiled in ${}^{29}$F
• Symmetry conserving configuration mixing method with cranked states
• Updated systematics of intermediate-energy single-nucleon removal cross sections
• Rotating deformed halo nuclei and shape decoupling effects
• The islands of shape coexistence within the Elliott and the proxy-SU(3) Models
• Evolution of the N=20 and 28 Shell Gaps and 2-particle-2-hole states in the FSU Interaction
• Extending the Southern Shore of the Island of Inversion to ${}^{28}$F
• Shape coexistence in even-even nuclei: A theoretical overview
• Mass Measurements Demonstrate a Strong N =28 Shell Gap in Argon
• Is the structure of 42Si understood?
• Single-particle and collective motion in unbound deformed ${}^{39}\text{Mg}$
• Hartree-Fock-Bogoliubov theory for odd-mass nuclei with a time-odd constraint and application to deformed halo nuclei
• Multiscale physics of atomic nuclei from first principles
• Double-step truncation procedure for large-scale shell-model calculations
• Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB
• Two-neutron halo structure of ${}^{31}$F and a novel pairing anti-halo effect
• The structure of ${}^{36}$Ca under the Coulomb magnifying glass
• First-principles results for electromagnetic properties of $sd$ shell nuclei
• The impact of the off-diagonal cross-shell interaction on ${}^{14}$C
• Examining the $N$ = 28 shell closure through high-precision mass measurements of ${}^{46-48}$Ar
• Normal and intruder configurations in ${}^{34}$Si populated in the ${\beta }^{-}$ decay of ${}^{34}$Mg and ${}^{34}$Al
• Density matrix renormalization group description of the island of inversion isotopes ${}^{28-33}$F
• Moments and Radii of exotic Na and Mg isotopes
• Re-examining the transition into the N=20 island of inversion: structure of ${}^{30}$Mg
• Broken mirror symmetry in ${}^{36}$S and ${}^{36}$Ca
• Neutron single-particle strength in silicon isotopes: Constraining the driving forces of shell evolution
• Role of quadrupole deformation and continuum effects in the "island of inversion'' nuclei ${}^{28,29,31}$F
• High-precision quadrupole moment reveals significant intruder component in 33Al20 ground state
• Exploring the halo character and dipole response in the dripline nucleus ${}^{31}$F
• Ab initio computations from ${}^{78}$Ni towards ${}^{70}$Ca along neutron number $N=50$
• Spectroscopy of ${}^{33}$Mg with knockout reactions
• The Structure of ${}^{33}$Si and the magicity of the N=20 gap at Z=14
• Simultaneous analysis of matter radii, transition probabilities, and excitation energies of Mg isotopes by angular-momentum-projected configuration-mixing calculations
• Role of hexadecapole deformation of projectile ${}^{28}$Si in heavy-ion fusion reactions near the Coulomb barrier
• Prediction of two-neutron halos in the $N=28$ isotones ${}^{40}$Mg and ${}^{39}$Na
• Weak binding effects on the structure of ${}^{40}$Mg
• Probing proton cross-shell excitations through the two-neutron removal from 38Ca
• Ab initio nuclear shape coexistence and emergence of island of inversion around $N=20$
• Structure of ${}^{30}$Mg explored via in-beam $\gamma$-ray spectroscopy
• Intruder configurations in ${}^{29}$Ne at the transition into the island of inversion: Detailed structure study of ${}^{28}$Ne
• Border of the Island of Inversion: Unbound states in ${}^{29}$Ne
• In-beam $\gamma$-ray spectroscopy of ${}^{32}$Mg via direct reactions
• Configuration interaction relativistic Hartree-Fock model
• Universal Effective Charges in the $sd$ and $fp$ Shells
• Evolution of $N=28$ shell closure in relativistic continuum Hartree-Bogoliubov theory
• ${}^{35,37,39}$S isotopes in $sd-pf$ space : Shell-model interpretation
• Search for the $1/2^{+}$ intruder state in ${}^{35}$P
• New isomeric transition in ${}^{36}$Mg: Bridging the N=20 and N=28 islands of inversion
• Ab initio study of island of inversion in odd-$A$ nuclei: Structure of ${}^{31,33}$Mg
• Deformation, halo, and bubble structure: A paradigm shift of exotic phenomena in light to medium mass nuclei
• Coulomb breakup of neutron-rich ${}^{29,30}$Na isotopes near the island of inversion
• Ab initio study in the island of inversion within the two-major-shell valence space
• Coexisting normal and intruder configurations in ${}^{32}$Mg
• Towards shell model interactions with credible uncertainties