Evolution of shell structure in neutron-rich calcium isotopes

Abstract

We employ interactions from chiral effective field theory and compute the binding energies and low-lying excitations of calcium isotopes with the coupled-cluster method. Effects of three-nucleon forces are included phenomenologically as in-medium two-nucleon interactions, and the coupling to the particle continuum is taken into account using a Berggren basis. The computed ground-state energies and the low-lying 2+ states for the isotopes 42,48,50,52Ca are in good agreement with data, and we predict the excitation energy of the first 2+ state in 54Ca at 1.9 MeV, displaying only a weak sub-shell closure. In the odd-mass nuclei 53,55,61Ca we find that the positive parity states deviate strongly from the naive shell model.

5 pages, 4 figures; small correction of effective 3NF and slight change of the corresponding parameters; updated figures and tables; main results and conclusions unchanged

References in corpus (13)

• Chiral effective field theory and nuclear forces
• Nuclear magic numbers: new features far from stability
• Improved nuclear matter calculations from chiral low-momentum interactions
• Shell Model in the Complex Energy Plane
• Three-Nucleon Low-Energy Constants from the Consistency of Interactions and Currents in Chiral Effective Field Theory
• Coupled-cluster theory for three-body Hamiltonians
• Shell Structure of Exotic Nuclei
• Medium-mass nuclei from chiral nucleon-nucleon interactions
• Cross-shell excitation in two-proton knockout: Structure of ${}^{52}$Ca
• Evidence for a change in the nuclear mass surface with the discovery of the most neutron-rich nuclei with 17<Z <25
• Chiral three-nucleon interaction and the carbon-14 dating beta decay
• Ab initio coupled-cluster theory for open-shell nuclei
• Study of neutron-rich calcium isotopes with a realistic shell-model interaction

Cited by in corpus (39)

• Three-body forces: From cold atoms to nuclei
• A nucleus-dependent valence-space approach to nuclear structure
• Nuclear charge radii: Density functional theory meets Bayesian neural networks
• Ab Initio Multi-Reference In-Medium Similarity Renormalization Group Calculations of Even Calcium and Nickel Isotopes
• Symmetry-guided large-scale shell-model theory
• Probing the N = 32 shell closure below the magic proton number Z = 20: Mass measurements of the exotic isotopes 52,53K
• Three-nucleon forces and spectroscopy of neutron-rich calcium isotopes
• A monopole-optimized effective interaction for tin isotopes
• Chiral EFT based nuclear forces: Achievements and challenges
• Toward a complete theory for predicting inclusive deuteron breakup away from stability
• Giant and pigmy dipole resonances in 4He, 16,22O, and 40Ca from chiral nucleon-nucleon interactions
• In-Medium Similarity Renormalization Group for Closed and Open-Shell Nuclei
• Three-body forces and proton-rich nuclei
• Elastic proton scattering of medium mass nuclei from coupled-cluster theory
• Living on the edge of stability, the limits of the nuclear landscape
• From the lightest nuclei to the equation of state of asymmetric nuclear matter with realistic nuclear interactions
• Ground-State Electromagnetic Moments of Calcium Isotopes
• Spectrum of shear modes in the neutron-star crust: Estimating the nuclear-physics uncertainties
• Structure and decays of nuclear three-body systems: the Gamow coupled-channel method in Jacobi coordinates
• Probing Nuclear forces beyond the drip-line using the mirror nuclei ${}^{16}$N and ${}^{16}$F
• Effects of three-nucleon spin-orbit interaction on isotope shifts of Pb nuclei
• Historical perspective and future prospects for nuclear interactions
• Continuum and Three-Nucleon Force Effects on 9Be Energy Levels
• Spectroscopy of ${}^{26}$F to probe proton-neutron forces close to the drip line
• Magicity of the ${}^{52}$Ca and ${}^{54}$Ca isotopes and tensor contribution within a mean--field approach
• Structure of 55Sc and development of the N=34 subshell closure
• A new tool in nuclear physics: Nuclear lattice simulations
• Effective proton-neutron interaction near the drip line from unbound states in ${}^{25,26}$F
• Effects of the tensor force on the ground and first $2^{+}$ states of the magic ${}^{54}$Ca nucleus
• Many-body Propagator Theory with Three-Body Interactions: a Path to Exotic Open Shell Isotopes
• Uncertainties of Euclidean Time Extrapolation in Lattice Effective Field Theory
• Alternative similarity renormalization group generators in nuclear structure calculations
• Nucleon-nucleon resonances at intermediate energies using a complex energy formalism
• Moving Beyond Chi-Squared in Nuclei and Neutron Stars
• The Hoyle state in Nuclear Lattice EFT
• Introduction of the one-body correlation operator in the unitary-model-operator approach
• Role of Three-Nucleon Forces in Neutron-Rich Nuclei Beyond 132Sn
• Ground-state energies and charge radii of ${}^4$He, ${}^{16}$O, ${}^{40}$Ca, and ${}^{56}$Ni in the unitary-model-operator approach
• Formal Developments for Lattice QCD with Applications to Hadronic Systems