Fine structure in the decay of U
Uの崩壊
Sun, M. D.*; Liu, Z.*; Huang, T. H.*; Zhang, W. Q.*; Andreyev, A. N.; Ding, B.*; Wang, J. G.*; Liu, X. Y.*; Lu, H. Y.*; Hou, D. S.*; Gan, Z. G.*; Ma, L.*; Yang, H. B.*; Zhang, Z. Y.*; Yu, L.*; Jiang, J.*; Wang, K. L.*; Wang, Y. S.*; Liu, M. L.*; Li, Z. H.*; Li, J.*; Wang, X.*; Feng, A. H.*; Lin, C. J.*; Sun, L. J.*; Ma, L. J.*; Zuo, W.*; Xu, H. S.*; Zhou, X. H.*; Xiao, G. Q.*; Qi, C.*; Zhang, F. S.*
Sun, M. D.*; Liu, Z.*; Huang, T. H.*; Zhang, W. Q.*; Andreyev, A. N.; Ding, B.*; Wang, J. G.*; Liu, X. Y.*; Lu, H. Y.*; Hou, D. S.*; Gan, Z. G.*; Ma, L.*; Yang, H. B.*; Zhang, Z. Y.*; Yu, L.*; Jiang, J.*; Wang, K. L.*; Wang, Y. S.*; Liu, M. L.*; Li, Z. H.*; Li, J.*; Wang, X.*; Feng, A. H.*; Lin, C. J.*; Sun, L. J.*; Ma, L. J.*; Zuo, W.*; Xu, H. S.*; Zhou, X. H.*; Xiao, G. Q.*; Qi, C.*; Zhang, F. S.*
Fine structure in the decay of U was observed in the fusion-evaporation reaction Re(Ar,p3n) by using fast digital pulse processing technique. Two -decay branches of U feeding the ground state and 244 keV excited state of Th were identified by establishing the decay chain UThRaRn. The -particle energy for the ground-state to ground-state transition of U was determined to be 8993(17) keV, 213 keV higher than the previous value, the half-life was updated to be 62s. Evolution of nuclear structure for =131 even- isotones from Po to U was discussed in the frameworks of nuclear mass and reduced -decay width, a weakening octupole deformation in the ground state of U relative to its lighter isotones Ra and Th was suggested.