Nakamura T, Vinodkumar A M, Sugimoto T, Aoi N, Baba H, Bazin D, Fukuda N, Gomi T, Hasegawa H, Imai N, Ishihara M, Kobayashi T, Kondo Y, Kubo T, Miura M, Motobayashi T, Otsu H, Saito A, Sakurai H, Shimoura S, Watanabe K, Watanabe Y X, Yakushiji T, Yanagisawa Y, Yoneda K
Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan.
Phys Rev Lett. 2006 Jun 30;96(25):252502. doi: 10.1103/PhysRevLett.96.252502.
An exclusive measurement has been made of the Coulomb dissociation of the two-neutron halo nucleus 11Li at 70 MeV/nucleon at RIKEN. Strong low-energy (soft) E1 excitation is observed, peaked at about Ex = 0.6 MeV with B(E1) = 1.42(18) e2fm2 for Erel < or = 3 MeV, which was largely missed in previous measurements. This excitation represents the strongest E1 transition ever observed at such low excitation energies. The spectrum is reproduced well by a three-body model with a strong two-neutron correlation, which is further supported by the E1 non-energy-weighted cluster sum rule.
在日本理化学研究所，对双中子晕核(^{11}Li)在70兆电子伏特每核子能量下的库仑解离进行了独家测量。观测到强烈的低能（软）E1激发，在相对能量(E_{rel}\leq3)兆电子伏特时，其峰值约为(E_x = 0.6)兆电子伏特，电偶极跃迁强度(B(E1)=1.42(18)e^2fm^2)，这在先前的测量中大多未被发现。这种激发代表了在如此低的激发能量下观测到的最强E1跃迁。该能谱通过具有强双中子关联的三体模型得到了很好的再现，并且电偶极非能量加权簇和规则进一步支持了这一结果。
