用BCS理论计算稀土核转动惯量的奇偶差

用BCS理论计算了稀土区偶偶核和奇A核的转动惯量.计算结果表明,尽管转动惯量的计算值系统地小于实验值,但实验上观测到的转动惯量奇偶差的大幅度变化能够用BCS理论定性地描述. 这个结论与人们普遍认为的BCS理论给出的奇A核转动惯量应比相邻的偶偶核基态转动惯量大15%的看法相悖,但却证实了20多年以前Gregory和Volkov等人得出的结论,有助于人们在BCS平均场理论框架下理解正常形变核中出现全同带的现象.

Odd-Even Differences in Moments of Inertia of Rare Earth Nuclei from the BCS Theory

BCS theory is used to calculate the moments of inertia (Mol) of odd-A and even-even rare-earth nuclei. It is found that the large fluctuations of the odd-even differences in MoI can be repreduced through the BCS calculations, although the MoI values calculated both for odd-A and even-even nuclei are systematically smaller then the experimental data. Contrary to the common assertion that the MoI value of odd-A nuclei are some 15% larger than that of the neighboring even-even nuclei in the BCS theory, our results confirm the conclusions made by Gregory Volkov over tWo decades ago. It seems helpful to understand the appearance of normally deformed identical bands in an odd-A nucleus and its evenreven neighbors Under the mean-field (BCS) approximation.