Negret A, Adachi T, Barrett B R, Bäumer C, van den Berg A M, Berg G P A, von Brentano P, Frekers D, De Frenne D, Fujita H, Fujita K, Fujita Y, Grewe E-W, Haefner P, Harakeh M N, Hatanaka K, Heyde K, Hunyadi M, Jacobs E, Kalmykov Y, Korff A, Nakanishi K, Navrátil P, von Neumann-Cosel P, Popescu L, Rakers S, Richter A, Ryezayeva N, Sakemi Y, Shevchenko A, Shimbara Y, Shimizu Y, Tameshige Y, Tamii A, Uchida M, Vary J, Wörtche H J, Yosoi M, Zamick L
Vakgroep Subatomaire en Stralingsfysica, Universiteit Gent, Proeftuinstraat 86, 9000 Gent, Belgium.
Phys Rev Lett. 2006 Aug 11;97(6):062502. doi: 10.1103/PhysRevLett.97.062502. Epub 2006 Aug 7.
A new experimental approach to the famous problem of the anomalously slow Gamow-Teller (GT) transitions in the beta decay of the A=14 multiplet is presented. The GT strength distributions to excited states in 14C and 14O were studied in high-resolution (d,2He) and (3He,t) charge-exchange reactions on 14N. No-core shell-model calculations capable of reproducing the suppression of the beta decays predict a selective excitation of Jpi=2+ states. The experimental confirmation represents a validation of the assumptions about the underlying structure of the 14N ground state wave function. However, the fragmentation of the GT strength over three 2+ final states remains a fundamental issue not explained by the present no-core shell model using a 6homega model space, suggesting possibly the need to include cluster structure in these light nuclei in a consistent way.
提出了一种针对A = 14多重态β衰变中异常缓慢的伽莫夫-特勒（GT）跃迁这一著名问题的新实验方法。通过对14N进行高分辨率的(d,2He)和(3He,t)电荷交换反应，研究了14C和14O中激发态的GT强度分布。能够再现β衰变抑制的无芯壳模型计算预测Jπ = 2+态的选择性激发。实验证实代表了对14N基态波函数潜在结构假设的验证。然而，GT强度在三个2+末态上的碎片化仍然是当前使用6ω模型空间的无芯壳模型无法解释的一个基本问题，这表明可能需要以一致的方式在这些轻核中纳入团簇结构。
