Negative Parity States in $^{39}$Cl Configured by Crossing Major Shell Orbits
Long-Chun Tao1,2, Y. Ichikawa2, Cen-Xi Yuan3, Y. Ishibashi2,4, A. Takamine2, A. Gladkov2,5, T. Fujita2,6, K. Asahi2,7, T. Egami8, C. Funayama7, K. Imamura2,9, Jian-Ling Lou1, T. Kawaguchi2,8, S. Kojima7, T. Nishizaka8, T. Sato2,7, D. Tominaga8, Xiao-Fei Yang1, H. Yamazaki2, Yan-Lin Ye1**, H. Ueno2
1School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 2RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan 3Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai 519082 4Department of Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan 5Department of Physics, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 702-701, South Korea 6Department of Physics, Osaka University, Machikaneyama 1-1 Toyonaka, Osaka 560-0034, Japan 7Department of Physics, Tokyo Institute of Technology, 2-12-1 Oh-okayama, Meguro, Tokyo 152-8551, Japan 8Department of Advanced Sciences, Hosei University, 3-7-2 Kajino-cho, Koganei, Tokyo 184-8584, Japan 9Department of Physics, Meiji University, 1-1-1 Higashi-Mita, Tama, Kawasaki, Kanagawa 214-8571, Japan
Abstract：Traditional "magic numbers" were once regarded as immutable throughout the nuclear chart. However, unexpected changes were found for unstable nuclei around $N=20$. With both proton and neutron numbers around the magic number of 20, the neutron-rich $^{39}$Cl isotope provides a good test case for the study of the quantum-state evolution across the major shell. In the present work, the negative parity states in $^{39}$Cl are investigated through the $\beta$ decay spectroscopy of $^{39}$S. Newly observed $\gamma$ transitions together with a new state are assigned into the level scheme of $^{39}$Cl. The spin parity of ${5/2}^{-}$ for the lowest negative parity state in $^{39}$Cl is reconfirmed using the combined $\gamma$ transition information. These systematic observations of the negative parity states in $^{39}$Cl allow a comprehensive comparison with the theoretical descriptions. The lowest ${5/2}^{-}$ state in $^{39}$Cl remains exotic in terms of comparisons with existing theoretical calculations and with the neighboring isotopes having similar single-particle configurations. Further experimental and theoretical investigations are suggested.
(β-decay;double β-decay; electron and muon capture)
引用本文:
. [J]. 中国物理快报, 2019, 36(6): 62101-.
Long-Chun Tao, Y. Ichikawa, Cen-Xi Yuan, Y. Ishibashi, A. Takamine, A. Gladkov, T. Fujita, K. Asahi, T. Egami, C. Funayama, K. Imamura, Jian-Ling Lou, T. Kawaguchi, S. Kojima, T. Nishizaka, T. Sato, D. Tominaga, Xiao-Fei Yang, H. Yamazaki, Yan-Lin Ye, H. Ueno. Negative Parity States in $^{39}$Cl Configured by Crossing Major Shell Orbits. Chin. Phys. Lett., 2019, 36(6): 62101-.
2019, Vol. 36 
