Global properties of fp-shell interactions in many-nucleon systems

Abstract

Spectral distribution theory, which can be used to compare microscopic interactions over a broad range of nuclei, is applied in an analysis of two modern effective interactions based on the realistic CD-Bonn potential for 0 Ω no-core shell model calculations in the f p shell, as well as in a comparison of these with the realistic shell-model GXPF1 interaction. In particular, we explore the ability of these interaction to account for the development of isovector pairing correlations and collective rotational motion in the f p shell. Our findings expose the similarities of these two-body interactions, especially as this relates to their pairing and rotational characteristics. Further, the GXPF1 interaction is used to determine the strength parameter of a quadrupole term that can be used to augment an isovector-pairing model interaction with Sp(4) dynamical symmetry, which in turn is shown to yield reasonable agreement with the low-lying energy spectra of 58 Ni and 58 Cu.

Exact isovector pairing in a shell-model framework: Role of proton-neutron correlations in isobaric analog states

“…Furthermore, the wave functions for the lowest isobaric analog 0 + states in 12 B, 12 C, and 12 N are expected to FIG. 1: (Color online) Theoretical energy spectra (colored shapes) compared to experiment (black crosses) for 0 + ; 0, .., 3 binding energies and lowest isobaric analog 0 + ; 0, .., 3 excited states of isotopes above and below the (a) 16 O core; (b) 40 Ca core; (c) 56 Ni core.…”

“…The present model, which accounts for both pn and likeparticle pairing, has been successfully applied to even-A nuclei for up to six particles above and below the 16 O, 40 Ca, and 56 Ni cores. In particular, using only two adjustable parameters, G and α, and experimentally deduced single-particle energies we calculate exact solutions for the J π = 0 + binding energies in even-even (ee) nuclei and the lowest isobaric analog 0 + excited states in oddodd (oo) nuclei (which correspond to the ground state of the even-even neighbor), together with pair-excitation 0 + states.…”

“…. , 3 states of ee and oo nuclei for up to six particles above and below the 16 O, 40 Ca, and 56 Ni cores (Fig. 1).…”

Symmetry-guided large-scale shell-model theory

“…Convergence to the shell-model results improves as higher-order energy moments are taken into account or toward the limit of many particles occupying a much larger available single-particle space. The theory provides the means to calculate important average contributions, nuclear level densities, degree of symmetry violation such as parity/time-reversal violation, nuclear structure and reactions, quantum chaos measures, as well as to understand dominant features of realistic N N interactions (see, e.g., [258]) and the effect of SRG-induced three-body forces [259] (see the book [260] on SDT and its applications).…”

Similarity renormalization group and many-body effects in multiparticle systems

“…The SDT approach has been successfully applied to studies of energy spectra and reactions for p-, sd, and fp-shell nuclei [18][19][20][21][22][23], as well as for understanding dominant features and differences among sd-shell realistic effective interactions [24,25]. Recent applications include explorations on quantum chaos, nuclear structure, and parity/time-reversal violation (for example, see [13,[26][27][28][29][30]). In the present study, we do not utilize the SDT microscopic approach but rather make use of tools developed in SDT.…”