Gamow-Teller strength in the 54Fe(p,n)54Co reaction at 135 MeV.
Gamow-Teller strength in the 54Fe(p,n)54Co reaction at 135 MeV.
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54Fe(p,n)54Co 反应中 135 MeV 的 Gamow-Teller 强度。
DOI：
10.1103/physrevc.41.1474
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Foster
中科院分区：
文献类型：
--
作者：
Anderson;Lebo;Baldwin;Chittrakarn;Madey;Watson;Foster
用飞行时间技术研究了135 MeV下的{sup 54}Fe({tal p}，{tal n}){sup 54}Co反应。在125m的大体积平均时间计数器中，以245keV的能量分辨率探测到了中子，其前向角谱主要由1个角分布特征为{Delta}{ital L}=0的{sup+}态的激发所主导，在0{°}处达到峰值。1{sup+}激发的强度被解释为相当于在β衰变中激发的Gamow-Teller(GT)强度。这种强度被观察到是高度分散的；GT强度在30多个州被确定。根据假设集中在0{sup+}等压类基态的费米强度{italB}(F)，求出了相应的强度。在离散状态下观察到的总的{italB}(GT{负})强度，与从({italn}，{italp})反应获得的{italB}(gt+)强度相结合，产生了3({italN}{-}{italZ})求和规则的48%的下限。在背景和准自由散射背景之上的连续体中加入{Delta}{ital L}=0强度，使这一下限增加到73%。如果考虑在整个背景和连续统中观察到的{Delta}{tal L}=0的强度，直到{italE}{sub{italx}}=25 MeV，则可能满足整体更多的和规则。观测到的GT强度分布与截断的1{italf}-2{italp}壳体模型计算符合得很好。
The {sup 54}Fe({ital p},{ital n}){sup 54}Co reaction was studied at 135 MeV by the time-of-flight technique. Neutrons were detected with an energy resolution of 245 keV in large-volume, mean-timed counters at a flight path of 125 m. The forward-angle spectra are dominated by the excitation of 1{sup +} states with characteristic {Delta}{ital l}=0 angular distributions peaked at 0{degree}. The strengths of the 1{sup +} excitations are interpreted as being equivalent to Gamow-Teller (GT) strengths excited in beta decay. This strength is observed to be highly fragmented; GT strength is identified in more than 30 states. The {ital B}(GT{minus}) strength is obtained relative to the Fermi strength {ital B}(F) assumed to be concentrated in the 0{sup +}, isobaric-analog ground state. The total {ital B}(GT{minus}) strength observed in discrete states, combined with the {ital B}(GT+) strength obtained from the ({ital n},{ital p}) reaction, yields a lower limit of 48 percent of the 3({ital N}{minus}{ital Z}) sum rule. Inclusion of {Delta}{ital l}=0 strength in the background and continuum above a quasifree scattering background increases this lower limit to 73 percent. If one considers the {Delta}{ital l}=0 strength observed in the full background and continuum up to {ital E}{sub {ital x}}=25 MeV, the entiremore » sum rule may be satisfied. The observed distribution of GT strength is in good agreement with a truncated 1{ital f}-2{ital p} shell-model calculation.« less