English

A two-neutron halo is unveiled in $^{29}$F

Nuclear Experiment 2020-06-08 v1 Nuclear Theory

Abstract

We report the measurement of reaction cross sections (σRex\sigma_R^{\rm ex}) of 27,29^{27,29}F with a carbon target at RIKEN. The unexpectedly large σRex\sigma_R^{\rm ex} and derived matter radius identify 29^{29}F as the heaviest two-neutron Borromean halo to date. The halo is attributed to neutrons occupying the 2p3/22p_{3/2} orbital, thereby vanishing the shell closure associated with the neutron number N=20N = 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^{27}F but are challenged for 29^{29}F.

Keywords

Cite

@article{arxiv.2005.09492,
  title  = {A two-neutron halo is unveiled in $^{29}$F},
  author = {S. Bagchi and R. Kanungo and Y. K. Tanaka and H. Geissel and P. Doornenbal and W. Horiuchi and G. Hagen and T. Suzuki and N. Tsunoda and D. S. Ahn and H. Baba and K. Behr and F. Browne and S. Chen and M. L. Cortés and A. Estradé and N. Fukuda and M. Holl and K. Itahashi and N. Iwasa and G. R. Jansen and W. G. Jiang and S. Kaur and A. O. Macchiavelli and S. Y. Matsumoto and S. Momiyama and I. Murray and T. Nakamura and S. J. Novario and H. J. Ong and T. Otsuka and T. Papenbrock and S. Paschalis and A. Prochazka and C. Scheidenberger and P. Schrock and Y. Shimizu and D. Steppenbeck and H. Sakurai and D. Suzuki and H. Suzuki and M. Takechi and H. Takeda and S. Takeuchi and R. Taniuchi and K. Wimmer and K. Yoshida},
  journal= {arXiv preprint arXiv:2005.09492},
  year   = {2020}
}

Comments

8 pages, 4 figures