Probing effective nucleon-nucleon interaction at band termination

Low-energy nuclear structure is not sensitive enough to resolve fine details of nucleon-nucleon (NN) interaction. Insensitivity of infrared physics to the details of short-range strong interaction allows for consistent, free of ultraviolet divergences, formulation of local theory at the level of local energy density functional (LEDF) including, on the same footing, both particle-hole as well as particle-particle channels. Major difficulty is related to parameterization of the nuclear LEDF and its density dependence. It is argued that structural simplicity of terminating or isomeric states offers invaluable source of informations that can be used for fine-tuning of the NN interaction in general and the nuclear LEDF parameters in particular. Practical applications of terminating states at the level of LEDF and nuclear shell-model are discussed.Comment: Invited talk presented at the XIII Nuclear Physics Workshop, Kazimierz Dolny, Sept. 27 - Oct. 1, Poland; submitted to IJMP

Wigner energy, odd-even mass staggering and the time-odd mean-fields

Various properties of single-particle Hartree-Fock ground-state solutions in $N\sim Z$ nuclei are investigated. The emphasis is on a role of single-particle mean-field in odd-even mass staggering. It is shown that, unlike in traditional scenario originating from the Fermi gas or macroscopic models, the symmetry energy contribution to odd-even mass staggering is nearly cancelled by the contribution coming from the average level density. It allows to construct indicators probing both pairing as well as mean-field components to the odd-even mass staggering. The impact of the single-particle Hartree-Fock field on Wigner energy and residual $pn$ interaction in odd-odd nuclei is also discussed.Comment: Plenary talk presented at Nuclear Structure'98, Gatlinburg, Tenn., USA, August 10-15, 1998, 10 LaTeX pages, 7 postscript figures, styles: aipproc2.sty, epsfig.st

Nucleonic Shells and Nuclear Masses

The binding energy of an isotope is a sensitive indicator of the underlying shell structure as it reflects the net energy content of a nucleus. Since magic nuclei are significantly lighter, or more bound, compared to their neighbors, the presence of nucleonic shell structure makes an imprint on nuclear masses. In this work, using a carefully designed binding-energy indicator, we catalog the appearance of spherical and deformed shell and subshell closures throughout the nuclear landscape. After presenting experimental evidence for shell and subshell closures as seen through the lens of nuclear masses, we study the ability of global nuclear mass models to predict local binding-energy variations related to shell effects.Comment: 12 pages, 8 figures, 1 tabl

Strong-interaction Isospin-symmetry Breaking Within the Density Functional Theory

The conventional Skyrme interaction is generalized by adding zerorange charge-symmetry-breaking and charge-independence-breaking terms, and the corresponding energy density functional is derived. It is shown that the extended model accounts for experimental values of mirror and triplet displacement energies (MDEs and TDEs) in sd-shell isospin triplets with, on average, ∼ 100 keV precision using only two additional adjustable coupling constants. Moreover, the model is able to reproduce, for the first time, the A = 4n versus A = 4n + 2 staggering of the TDEs.peerReviewe