Abstract: Within the O(6) limit of s-d IBM1, the effective three-body potential between the interactions of d-bosons is introduced with the consideration of octupole states, which are produced by a f-boson plus (N-1) s-d. Then the analytic expressions of negative parity energy spectrum formula is obtained. Also the negative parity energy spectra of even-even nuclei ^{118, 120}Xe and ^{124, 126, 128, 130}Ba are calculated. The good fits with the experimental data are obtained, and Staggering phenomena is quantitatively analyzed with Staggering index formula in negative parity energy spectra.

Key words: effective three-body potential, octupole states, energy staggering

摘要： 在s-d IBM1的O(6)极限下，引入d玻色子之间相互作用的等效三体势，考虑f玻色子产生的八极态，导出了负宇称态能谱解析表达式，并对过渡区^{118, 120}Xe和^{124, 126, 128, 130}Ba 6个偶偶核的负宇称带进行了能谱计算，得到了与实验能谱符合很好的结果，然后用Staggering指数定量分析了负宇称态能谱中的Staggering现象。

关键词: 等效三体势, 八极态, 能量Staggering