Proton-neutron alignment in the yrast states of ${}^{66}$Ge and ${}^{68}$Ge

Abstract

The ${}^{66}$Ge and ${}^{68}$Ge nuclei are studied by means of the shell model with the extended $P+QQ$ Hamiltonian, which succeeds in reproducing experimentally observed energy levels, moments of inertia and other properties. The investigation using the reliable wave-functions predicts T=0, J=9 one-proton-one-neutron ($1p1n$) alignment in the $g_{9/2}$ orbit, at high spins ($14_1^{+}$, $16_1^{+}$ and $18_1^{+}$) in these $N\approx Z$ even-even nuclei. It is shown that a series of the even-$J$ positive-parity yrast states (observed up to $26_1^{+}$ for ${}^{68}$Ge) consists of the ground-state band and successive three bands with different types of particle alignments (two-neutron, $1p1n$, two-proton-two-neutron) in the $g_{9/2}$ orbit.

4 pages, 5 figures, to be published in Pyhs. Rev. C

References in corpus (1)

• Different particle alignments in N \approx Z Ru isotopes studied by the shell model

Cited by in corpus (6)

• Overview of Neutron-Proton Pairing
• Shape transition and oblate-prolate coexistence in N=Z fpg-shell nuclei
• Enhancement of $B(E2)$ and low excitation of the second 0${}^{+}$ state near N=40 in Ge isotopes
• Structure of isomeric states in 66As and 67As
• Particle alignments and shape change in ${}^{66}$Ge and ${}^{68}$Ge
• Unique features of structure in an odd-proton $N\approx Z$ nucleus ${}^{69}$As