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arXiv 1602.01485nucl-ex
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丰中子$^{144}$ Ba中八极形变的直接证据

Direct Evidence of Octupole Deformation in Neutron-Rich $^{144}$Ba

B. Bucher, S. Zhu, C. Y. Wu, R. V. F. Janssens, D. Cline, A. B. Hayes, M. Albers, A. D. Ayangeakaa, P. A. Butler, C. M. Campbell, M. P. Carpenter, C. J. Chiara,… 展开作者

B. Bucher, S. Zhu, C. Y. Wu, R. V. F. Janssens, D. Cline, A. B. Hayes, M. Albers, A. D. Ayangeakaa, P. A. Butler, C. M. Campbell, M. P. Carpenter, C. J. Chiara, J. A. Clark, H. L. Crawford, M. Cromaz, H. M. David, C. Dickerson, E. T. Gregor, J. Harker, C. R. Hoffman, B. P. Kay, F. G. Kondev, A. Korichi, T. Lauritsen, A. O. Macchiavelli, R. C. Pardo, A. Richard, M. A. Riley, G. Savard, M. Scheck, D. Seweryniak, M. K. Smith, R. Vondrasek, A. Wiens

摘要:

丰中子核$^{144}$ Ba($t_{1/2}$ =11.5 s)预期在质量数$A$小于200的核中表现出最强的八极相关。到目前为止,这种强相关性的间接证据已经从观测中推断出来,例如增强的$E1$跃迁和基态带中交错的正负宇称能级。在这个实验中,八极强度直接测量的亚势垒,多步库仑激发后加速的650 MeV的$^{144}$钡束上的1.0 mg/cm的$^2$ $^{208}$铅目标。矩阵元素的测量值$\langle 3_1^- \| \mathcal{M}(E3) \| 0_1^+ \rangle=0.65(^{+17}_{-23})$ $e$ b $^{3/2}$对应于48($^{+25}_{-34}$)W. u的降低的$B(E3)$跃迁概率。这一结果代表了一个明确的确定八极集体,是大于任何可用的理论预测,并与八极形变是一致的。

英文摘要:

The neutron-rich nucleus $^{144}$Ba ($t_{1/2}$=11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers $A$ less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced $E1$ transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multi-step Coulomb excitation of a post-accelerated 650-MeV $^{144}$Ba beam on a 1.0-mg/cm$^2$ $^{208}$Pb target. The measured value of the matrix element, $\langle 3_1^- \| \mathcal{M}(E3) \| 0_1^+ \rangle=0.65(^{+17}_{-23})$ $e$b$^{3/2}$, corresponds to a reduced $B(E3)$ transition probability of 48($^{+25}_{-34}$) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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