Structure of upper g9/2-shell nuclei and shape effect in the 94Ag isomeric states

Abstract

Using a shell model which is capable of describing the spectra of upper $g_{9/2}$-shell nuclei close to the $N=Z$ line, we study the structure of two isomeric states $7^{+}$ and $21^{+}$ in the odd-odd $N=Z$ nucleus ${}^{94}$Ag. It is found that both isomeric states exhibit a large collectivity. The $7^{+}$ state is oblately deformed, and is suggested to be a shape isomer in nature. The $21^{+}$ state becomes isomeric because of level inversion of the $19^{+}$ and $21^{+}$ states due to core excitations across the $N=Z=50$ shell gap. Calculation of spectroscopic quadrupole moment indicates clearly an enhancement in these states due to the core excitations. However, the present shell model calculation that produces the $19^{+}$-$21^{+}$ level inversion cannot accept the large-deformation picture of Mukha {\it et al.} in Nature {\bf 439}, 298 (2006).

10 pages, 14 figures, accepted for publication in Phys. Rev. C

References in corpus (6)

• New effective interaction for $pf$-shell nuclei and its implications for the stability of the $N$=$Z$=28 closed core
• Shape transition and oblate-prolate coexistence in N=Z fpg-shell nuclei
• Nuclear structure of the exotic mass region along the rp process path
• Structure of isomeric states in 66As and 67As
• Different particle alignments in N \approx Z Ru isotopes studied by the shell model
• Particle alignments and shape change in ${}^{66}$Ge and ${}^{68}$Ge

Cited by in corpus (5)

• Overview of Neutron-Proton Pairing
• Mass Measurements and Implications for the Energy of the High-Spin Isomer in 94Ag
• A Hot Cavity Laser Ion Source at IGISOL
• Development of a low-energy radioactive ion beam facility for the MARA separator
• High-spin μs isomeric states in 96Ag