First identification of excited states in theN=Z+1nucleusRu89

Abstract

High-spin excited states have been identified for the first time in the $N=Z+1$ nucleus $^{89}\mathrm{Ru}$ with the reaction $^{54}\mathrm{Fe}(^{40}\mathrm{Ca},\ensuremath{\alpha}n\ensuremath{\gamma})$ at 130 MeV, using the GASP array, the ISIS Silicon array, and the $n$-Ring detector system. The observed structure is discussed within systematics of the $N=45$ isotones and is compared with shell model calculations.