From spin to pseudospin symmetry: The origin of magic numbers in nuclear structure

Abstract

Magic numbers lie at the heart of nuclear structure, reflecting enhanced stability in nuclei with closed shells. While the emergence of magic numbers beyond 20 is commonly attributed to strong spin-orbit coupling, the microscopic origin of the spin-orbit potential remains elusive, owing to its dependence on the resolution scale and renormalization scheme of nuclear forces. Here, we investigate the evolution of shell structure with varying momentum resolution in nuclear interactions derived from chiral effective field theory, using the similarity renormalization group to link different scales. We uncover a novel transition from spin symmetry to pseudospin symmetry as the resolution scale decreases, during which magic numbers emerge naturally. A similar pattern is found in calculations using relativistic one-boson-exchange potentials, underscoring the robustness of the phenomenon. This establishes a direct connection between realistic nuclear forces with a high resolution scale and effective nuclear forces at coarse-grained scales, offering a first-principles explanation for the origin of magic numbers and pseudospin symmetry in nuclear shell structure, and new insights into the structure of exotic nuclei far from stability.

arXiv comment6 pages with 3 figures

References in corpus (50)

• Modern Theory of Nuclear Forces
• Chiral effective field theory and nuclear forces
• Accurate Charge-Dependent Nucleon-Nucleon Potential at Fourth Order of Chiral Perturbation Theory
• Relativistic Continuum Hartree Bogoliubov Theory for Ground State Properties of Exotic Nuclei
• Pseudo-spin as a Relativistic Symmetry
• Improved nuclear matter calculations from chiral low-momentum interactions
• Coupled-cluster computations of atomic nuclei
• Three-body forces and the limit of oxygen isotopes
• From low-momentum interactions to nuclear structure
• The In-Medium Similarity Renormalization Group: A Novel Ab Initio Method for Nuclei
• Similarity Renormalization Group for Nucleon-Nucleon Interactions
• Evolution of shell structure in exotic nuclei
• Hidden pseudospin and spin symmetries and their origins in atomic nuclei
• The pseudo-spin symmetry in Zr and Sn isotopes from the proton drip line to the neutron drip line
• Evolution of shell structure in neutron-rich calcium isotopes
• In-Medium Similarity Renormalization Group for Nuclei
• Spin symmetry in the anti-nucleon spectrum
• Evolution of Nuclear Many-Body Forces with the Similarity Renormalization Group
• Continuum effects and three-nucleon forces in neutron-rich oxygen isotopes
• Ab Initio Calculations of Even Oxygen Isotopes with Chiral Two- Plus Three-Nucleon Interactions
• Shell Structure and $\rho$-Tensor Correlations in Density-Dependent Relativistic Hartree-Fock theory
• Novel chiral Hamiltonian and observables in light and medium-mass nuclei
• On the Relativistic Foundations of Pseudospin Symmetry in Nuclei
• Isotopic chains around oxygen from evolved chiral two- and three-nucleon interactions
• Accurate bulk properties of nuclei from $A=2$ to $\infty$ from potentials with $\Delta$ isobars
• Low-momentum interaction in few-nucleon systems
• Three-body forces and shell structure in calcium isotopes
• Three-Nucleon Forces: Implementation and Applications to Atomic Nuclei and Dense Matter
• Towards an ab initio covariant density functional for nuclear structure
• Ab Initio Multi-Reference In-Medium Similarity Renormalization Group Calculations of Even Calcium and Nickel Isotopes
• Hartree-Fock and Many-Body Perturbation Theory with Correlated Realistic NN-Interactions
• Chiral three-nucleon forces and the evolution of correlations along the oxygen isotopic chain
• Ab-initio self-consistent Gorkov-Green's function calculations of semi-magic nuclei - II. Numerical implementation at second order with a two-nucleon interaction
• Momentum space evolution of chiral three-nucleon forces
• In-Medium Similarity Renormalization Group for Closed and Open-Shell Nuclei
• Non-observable nature of the nuclear shell structure. Meaning, illustrations and consequences
• Ab initio computation of the 17F proton-halo state and resonances in A = 17 nuclei
• In-medium similarity renormalization group with three-body operators
• Ab-initio approach to effective single-particle energies in doubly closed shell nuclei
• Fully self-consistent relativistic Brueckner-Hartree-Fock theory for finite nuclei
• \texttt{NuHamil}: A numerical code to generate nuclear two- and three-body matrix elements from chiral effective field theory
• Nuclear energy density functional from chiral two- and three-nucleon interactions
• Pseudo-spin symmetry restoration and the in-medium balance between nuclear attractive and repulsive interactions
• Nuclear energy density functional from chiral pion-nucleon dynamics revisited
• Factorized Approximation to the IMSRG(3)
• Three-body spin-orbit forces from chiral two-pion exchange
• Saturation of nuclear matter in the relativistic Brueckner Hatree-Fock approach with a leading order covariant chiral nuclear force
• Note on spin-orbit interactions in nuclei and hypernuclei
• Reconciling light nuclei and nuclear matter: relativistic $abinitio$ calculations
• Uncovering the mechanism of chiral three-nucleon force in driving spin-orbit splitting