New high spin states and band termination in {sup 83}Y and {sup 84}Zr
New high spin states and band termination in {sup 83}Y and {sup 84}Zr
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{sup 83}Y 和 {sup 84}Zr 中新的高自旋态和能带终止
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
A. Machiavelli
中科院分区：
文献类型：
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作者：
T. Johnson;A. Aprahamian;C. Lister;D. Blumenthal;B. Crowell;P. Chowdhury;P. Fallon;A. Machiavelli
利用伽玛球早期实现阵列和{sup 58}Ni（{sup 29}Si,3p）在110 MeV下的反应，观察到{sup 83}Y到I{sup {pi}}=59/2{sup +}和53/2{sup{负}}的高自旋yast态的伽玛衰变。由于在所有波段观测到几个新的跃迁，电平方案得到了实质性的扩展。一系列跃迁进入I{sup {pi}}=47/2{sup +}以上的正宇称带，似乎与高自旋下预期的非集体扁圆结构一致。在{sup 84}Zr的数据中发现了类似的级联。发现了有利的负宇称带的新分叉，这可能是由于中子对准使核心极化成不同的形状。这表明在{sup 83}Y中发现的{open_quotes}同分异构体{close_quote}{close_quote}带与在该区域发现的其他高k带具有相似的性质，其中多了一个连接跃迁。在不利的负奇偶带的寿命测量结果与曲柄计算相一致，曲柄计算预测了变形参数{β}{sub 2}{约}0.2的近扁圆形状。在非常高的自旋下，对线形的定性分析表明，在最后的序列中，集体的持久性一直持续到最高的激发。{版权所有}{ital 1997} {ital美国物理学会}«少
The gamma decay of high spin yrast states in {sup 83}Y up to I{sup {pi}}=59/2{sup +} and 53/2{sup {minus}} have been observed using the reaction {sup 58}Ni({sup 29}Si,3p) at 110 MeV and the Gammasphere Early Implementation Array. The level scheme has been substantially extended due to the observations of several new transitions in all of the bands. A sequence of transitions feeding into the positive parity yrast band above I{sup {pi}}=47/2{sup +} seems to be consistent with a noncollective oblate structure expected at these high spins. A similar cascade is found in the data for {sup 84}Zr. A new forking of the favored negative parity band is found which may be due to neutron alignment polarizing the core to a different shape. This suggests that the {open_quotes}isomeric{close_quote}{close_quote} band in {sup 83}Y, for which one more connecting transition was found, is of a similar nature to other high-K bands found in this region. Lifetime measurements in the unfavored negative parity band are consistent with cranking calculations which predict a nearly oblate shape with a deformation parameter {beta}{sub 2}{approx}0.2. A qualitative analysis of line shapes at very high spins suggests the persistence of collectivity in the yrast sequence to the highest excitationsmore » seen. {copyright} {ital 1997} {ital The American Physical Society}« less