Intruder structures in ${}^{32}$Si and ${}^{29}$Al

Abstract

We have studied ${}^{32}$Si and ${}^{29}$Al using ${}^{12}$C(${}^{22}$Ne,2p) and ${}^{12}$C(${}^{22}$Ne,$\hat{I}\pm$p) fusion-evaporation reactions. In both cases, we observed significant population of high-spin structures distinct from the ground-state yrast bands. In ${}^{32}$Si, most of the high-energy states feed into a $J^{\ddot{I}}€=5^{-}$ nanosecond isomer. In ${}^{29}$Al, we identified a rotor-like negative-parity band with a $J^{\ddot{I}}€=7/2^{-}$ band-head. Doppler shift lifetime measurements were performed for all observed states. These results were compared to shell model calculations and interpreted in terms of proton and neutron cross-shell excitation.

Accepted, Physical Review C