Large-scale shell-model calculations for unnatural-parity high-spin states in neutron-rich Cr and Fe isotopes

Abstract

We investigate unnatural-parity high-spin states in neutron-rich Cr and Fe isotopes using large-scale shell-model calculations. These shell-model calculations are carried out within the model space of $fp$-shell + $0g_{9/2}$ + $1d_{5/2}$ orbits with the truncation allowing $1\hslash \omega$ excitation of a neutron. The effective Hamiltonian consists of GXPF1Br for $fp$-shell orbits and $V_{\mathrm{MU}}$ with a modification for the other parts. The present shell-model calculations can describe and predict the energy levels of both natural- and unnatural-parity states up to the high-spin states in Cr and Fe isotopes with $N\le 35$. The total energy surfaces present the prolate deformations on the whole and indicate that the excitation of one neutron into the $0g_{9/2}$ orbit plays the role of enhancing the prolate deformation. For the positive(unnatural)-parity states in odd-mass Cr and Fe isotopes, their energy levels and prolate deformations indicate the decoupling limit of the particle-plus-rotor model. The sharp drop of the $9/2_1^{+}$ levels in going from $N=29$ to $N=35$ in odd-mass Cr and Fe isotopes is explained by the Fermi surface approaching the $\nu 0g_{9/2}$ orbit.

References in corpus (16)

• The Shell Model as Unified View of Nuclear Structure
• Magic numbers in exotic nuclei and spin-isospin properties of {\it NN} interaction
• Novel features of nuclear forces and shell evolution in exotic nuclei
• New effective interaction for $pf$-shell nuclei and its implications for the stability of the $N$=$Z$=28 closed core
• Shape transitions in exotic Si and S isotopes and tensor-force-driven Jahn-Teller effect
• Novel shape evolution in exotic Ni isotopes and configuration-dependent shell structure
• Spherical Shell Model description of rotational motion
• Cross-shell excitation in two-proton knockout: Structure of ${}^{52}$Ca
• Observation of isotonic symmetry for enhanced quadrupole collectivity in neutron-rich 62,64,66Fe isotopes at N=40
• Light Nuclei near Neutron and Proton Drip Lines in the Relativistic Mean-Field Theory
• Shell model study of single-particle and collective structure in neutron-rich Cr isotopes
• An Update of B(E2) Evaluation for 0+1 -> 2+1 Transitions in Even-Even Nuclei near N~Z~28
• Nuclear Structure Towards N=40 60Ca: In-beam gamma-ray Spectroscopy of 58,60Ti
• Variational procedure for nuclear shell-model calculations and energy-variance extrapolation
• Magnetic Moment of the Fragmentation Aligned 61Fe(9/2)+ Isomer
• Deformation around neutron-rich Cr isotopes in axially symmetric Skyrme-Hatree-Fock-Bogoliubov method

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