학술논문
Observation of the $\pi^2\sigma^2$-bond linear-chain molecular structure in $^{16}$C
Document Type
Working Paper
Author
Han, J. X.; Liu, Y.; Ye, Y. L.; Lou, J. L.; Yang, X. F.; Baba, T.; Kimura, M.; Yang, B.; Li, Z. H.; Li, Q. T.; Xu, J. Y.; Ge, Y. C.; Hua, H.; Yang, Z. H.; Wang, J. S.; Yang, Y. Y.; Ma, P.; Bai, Z.; Hu, Q.; Liu, W.; Ma, K.; Tao, L. C.; Jiang, Y.; Hu, L. Y.; Zang, H. L.; Feng, J.; Wu, H. Y.; Bai, S. W.; Li, G.; Yu, H. Z.; Huang, S. W.; Chen, Z. Q.; Sun, X. H.; Li, J. J.; Tan, Z. W.; Gao, Z. H.; Duan, F. F.; Tan, J. H.; Sun, S. Q.; Song, Y. S.
Source
Subject
Language
Abstract
Measurements of the $^2$H($^{16}$C,$^{16}$C$^{*}$$\rightarrow^4$He+$^{12}$Be or $^6$He+$^{10}$Be)$^2$H inelastic excitation and cluster-decay reactions have been carried out at a beam energy of about 23.5 MeV/u. A specially designed detection system, including one multi-layer silicon-strip telescope at around zero degrees, has allowed the high-efficiency three-fold coincident detection and therefore the event-by-event determination of the energy of the unstable nucleus beam. The decay paths from the $^{16}$C resonances to various states of the final $^{10}$Be or $^{12}$Be nucleus are recognized thanks to the well-resolved $Q$-value spectra. The reconstructed resonances at 16.5(1), 17.3(2), 19.4(1) and 21.6(2) MeV are assigned as the $0^+$, $2^+$, $4^+$ and $6^+$ members, respectively, of the positive-parity $(3/2_\pi^-)^2(1/2_\sigma^-)^2$-bond linear-chain molecular band in $^{16}$C, based on the angular correlation analysis for the 16.5 MeV state and the excellent agreement of decay patterns between the measurements and theoretical predictions. Moreover, another intriguing high-lying state was observed at 27.2(1) MeV which decays almost exclusively to the $\sim$6 MeV states of $^{10}$Be, in line with the newly predicted pure $\sigma$-bond linear-chain configuration.
Comment: 13 pages, 10 figures
Comment: 13 pages, 10 figures