학술논문
A two-neutron halo is unveiled in $^{29}$F
Document Type
Working Paper
Author
Bagchi, S.; Kanungo, R.; Tanaka, Y. K.; Geissel, H.; Doornenbal, P.; Horiuchi, W.; Hagen, G.; Suzuki, T.; Tsunoda, N.; Ahn, D. S.; Baba, H.; Behr, K.; Browne, F.; Chen, S.; Cortés, M. L.; Estradé, A.; Fukuda, N.; Holl, M.; Itahashi, K.; Iwasa, N.; Jansen, G. R.; Jiang, W. G.; Kaur, S.; Macchiavelli, A. O.; Matsumoto, S. Y.; Momiyama, S.; Murray, I.; Nakamura, T.; Novario, S. J.; Ong, H. J.; Otsuka, T.; Papenbrock, T.; Paschalis, S.; Prochazka, A.; Scheidenberger, C.; Schrock, P.; Shimizu, Y.; Steppenbeck, D.; Sakurai, H.; Suzuki, D.; Suzuki, H.; Takechi, M.; Takeda, H.; Takeuchi, S.; Taniuchi, R.; Wimmer, K.; Yoshida, K.
Source
Phys. Rev. Lett. 124, 222504 (2020)
Subject
Language
Abstract
We report the measurement of reaction cross sections ($\sigma_R^{\rm ex}$) of $^{27,29}$F with a carbon target at RIKEN. The unexpectedly large $\sigma_R^{\rm ex}$ and derived matter radius identify $^{29}$F as the heaviest two-neutron Borromean halo to date. The halo is attributed to neutrons occupying the $2p_{3/2}$ orbital, thereby vanishing the shell closure associated with the neutron number $N = 20$. The results are explained by state-of-the-art shell model calculations. Coupled-cluster computations based on effective field theories of the strong nuclear force describe the matter radius of $^{27}$F but are challenged for $^{29}$F.
Comment: 8 pages, 4 figures
Comment: 8 pages, 4 figures