A. Revel, F. M. Marques, O. Sorlin, T. Aumann, C. Caesar, M. Holl, V. Panin, M. Vandebrouck, F. Wamers, H. Alvarez-Pol, L. Atar, V. Avdeichikov, S. Beceiro-Novo… 展开作者
A. Revel, F. M. Marques, O. Sorlin, T. Aumann, C. Caesar, M. Holl, V. Panin, M. Vandebrouck, F. Wamers, H. Alvarez-Pol, L. Atar, V. Avdeichikov, S. Beceiro-Novo, D. Bemmerer, J. Benlliure, C. A. Bertulani, J. M. Boillos, K. Boretzky, M. J. G. Borge, M. Caamano, E. Casarejos, W. N. Catford, J. Cederkäll, M. Chartier, L. Chulkov, D. Cortina-Gil, E. Cravo, R. Crespo, U. Datta Pramanik, P. Diaz Fernandez, I. Dillmann, Z. Elekes, J. Enders, O. Ershova, A. Estrade, F. Farinon, L. M. Fraile, M. Freer, D. Galaviz, H. Geissel, R. Gernhauser, P. Golubev, K. Göbel, J. Hagdahl, T. Heftrich, M. Heil, M. Heine, A. Heinz, A. Henriques, A. Hufnagel, A. Ignatov, H. T. Johansson, B. Jonson, J. Kahlbow, N. Kalantar-Nayestanaki, R. Kanungo, A. Kelic-Heil, A. Knyazev, T. Kroll, N. Kurz, M. Labiche, C. Langer, T. Le Bleis, R. Lemmon, S. Lindberg, J. Machado, J. Marganiec, A. Movsesyan, E. Nacher, M. Najafi, E. Nikolskii, T. Nilsson, C. Nociforo, S. Paschalis, A. Perea, M. Petri, S. Pietri, R. Plag, R. Reifarth, G. Ribeiro, C. Rigollet, M. Roder, D. Rossi, D. Savran, H. Scheit, H. Simon, I. Syndikus, J. T. Taylor, O. Tengblad, R. Thies, Y. Togano, P. Velho, V. Volkov, A. Wagner, H. Weick, C. Wheldon, G. Wilson, J. S. Winfield, P. Woods, D. Yakorev, M. Zhukov, A. Zilges, K. Zuber
备注：
6 pages, 4 figures, accepted for publication in Phys. Rev. Lett
用高能核子敲除$^{19}$ N和$^{21}$ O次级束，研究了富中子$N\!=\!12$同位素$^{18}$ C和$^{20}$ O的中子对发射，使这两种同位素的未束缚态达到其双中子发射阈值以上15 MeV。三重碎片-$n$-$n$关联分析表明，$^{19}$ N $(-1p)^{18}$ C $^*\!\rightarrow^{16}$ C + $n$ + $n$的衰变明显地以直接对发射为主.两个中子的关联强度是有史以来观测到的最大的，这表明$^{14}$ C核心的主导地位，周围是以强关联对排列的四价中子。另一方面，在衰变$^{21}$ O $(-1n)^{20}$ O $^*\!\rightarrow^{18}$ O + $n$ + $n$中发现了一个顺序分支的显著竞争，这归因于它的形成是通过敲除一个深束缚的中子，打破了$^{16}$ O核心，减少了对的数量。
英文摘要：
The emission of neutron pairs from the neutron-rich $N\!=\!12$ isotones $^{18}$C and $^{20}$O has been studied by high-energy nucleon knockout from $^{19}$N and $^{21}$O secondary beams, populating unbound states of the two isotones up to 15~MeV above their two-neutron emission thresholds. The analysis of triple fragment-$n$-$n$ correlations shows that the decay $^{19}$N$(-1p)^{18}$C$^*\!\rightarrow^{16}$C+$n$+$n$ is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a $^{14}$C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay $^{21}$O$(-1n)^{20}$O$^*\!\rightarrow^{18}$O+$n$+$n$, attributed to its formation through the knockout of a deeply-bound neutron that breaks the $^{16}$O core and reduces the number of pairs.
Pairing strength in the relativistic mean-field theory determined from fission barrier heights of actinide nuclei and verified by pairing rotation and binding energies
Shell gaps and pn pairing interaction in N = Z nuclei
我们分析了观察到的壳层间隙N=Z核确定的结合能差。结果表明，壳层能隙可以用单粒子能级间距、类核子配对和质子-中子配对相互作用的综合贡献来描述。这一结论与Chasman在Phys. Rev. Lett. 99（2007）082501。对于双闭壳层N=Z核，用Woods-Saxon势计算的单粒子能级间距与从观察到的壳层能隙中减去nn对相互作用得到的结果非常接近.对于亚封闭或非封闭壳层N=Z核，pn配对相互作用被证明是重要的观察到的壳层间隙。
本文详细研究了分波效应中核力对原子核配对的贡献。对于T=1，J=0的配对，标准1 S 0通道以外的分波对原子核中的配对的形成起着有趣的作用。另外的贡献主要是由排斥3 P1分波。它们的作用，以及成对核子之间的自旋三重态核力，都受到自旋轨道伙伴相互作用的影响。我们探讨的影响，包括超出1 S 0通道的中子-中子配对间隙半魔同位素链的分波。此外，我们还证明了除了低j轨道外，核力更倾向于T=1，J=0而不是T=0，J=1配对.这与自由空间的动机相反，自由空间的动机表明在N=Z核中形成了类氘T=0对。T=0配对的抑制是因为3S 1强度分布在自旋轨道伙伴上，并且由于排斥1 P1通道和D波的影响。
