Multi-intruder structures in34P

Abstract

The available experimental information on ${}^{34}$P has been greatly increased through the analysis of $\ensuremath{\gamma}$ decays in coincidence with protons from the interaction of an ${}^{18}$O beam at 24 MeV with an ${}^{18}$O target. Light charged particles from the reaction were detected with Microball, and multiple $\ensuremath{\gamma}$-ray coincidences with Gammasphere. Many observed $\ensuremath{\gamma}$ transitions have been identified and placed in the level scheme. Additionally, for most states, spins have been assigned based on measured $\ensuremath{\gamma}$-ray angular distributions while parities were inferred from lifetimes determined through Doppler-broadened line-shape analysis. Most of the states observed have been interpreted in terms of shell-model calculations using the WBP-a and SDPF-NR interactions having one particle in the $0{f}_{7/2}$ or $1{p}_{3/2}$ orbital. The two calculations agree almost equally well with the data resulting in root-mean-square differences of about 200 keV. However, a few high-lying states observed with long lifetimes challenge current calculations. Two of these may be associated with stretched $\ensuremath{\pi}{f}_{7/2}\ensuremath{\bigotimes}\ensuremath{\nu}{f}_{7/2}$ states, but the calculations overpredict their energies by 2--3 MeV. Furthermore, a long-lived 7919-keV state is established for which no explanation is available at present.