Evidence for a Nucleon-Nucleus Spin-Spin Interaction inBe9

Abstract

Detailed examination of the $\gamma$-ray spectrum due to the reaction ${}_{}{}^9{}_{}{}^{}\mathrm{Be}(n, \gamma ){}_{}{}^{10}{}_{}{}^{}\mathrm{Be}$ reveals the presence of a spin-spin interaction of magnitude $V_{I\sigma }=1.65\mathrm{}\pm 0.15$ MeV. In addition, the spectroscopic factor of the second $0^{+}$ state at 6190 keV is determined to be $S_{\mathrm{dp}}=0.032\mathrm{}\pm 0.005$ which suggests that this state is an intruder state.