自旋相关的Λ超子与核子间张量相互作用的首次观测

First observation of the ΛN tensor interaction

超核γ谱学国际合作组在用超球γ谱仪(Hyperball)进行的1Λ6O的γ射线谱学测量中,观察到由1Λ6O的6.6MeV12-激发态跃迁到基态自旋翻转二重态(11-和0-)之间的两条γ射线.由这两条γ射线的能量差得到基态二重态之间的能量间隔为26.4±1.6(统计误差)±0.5(系统误差)keV,并由此推导出ΛN之间的张量相互作用强度T=0.03MeV.实验还测定了Λ16O的12-激发态的激发能为6561.7±1.1(统计误差)±1.7(系统误差)keV.

In a ^16∧O γ-ray spectroscopy experiment with HYPERBALL performed by an international team,two γ-ray transitions from the 6.6MeV excited 1^- 2 state to both ground-state spin-doublet members 1^- 1 and 0^- have been observed. The measured ground-state doublet spacing is 26.4 ± 1.6 （stat） ± 0.5 （syst） keV. Thus a small but nonzero strength of the ∧N tensor interaction is deduced to be T = ＋ 0.03 MeV. The excitation energy of the 1^- 2 state is also determined to be 6561.7 ± 1.1（stat） ± 1.7（syst） keV.