Revisit to the yield ratio of triton and $^3$He as an indicator of neutron-rich neck emission

Author:

Yijie Wang, Mengting Wan, Xinyue Diao, Sheng Xiao, Yuhao Qin, Zhi Qin, Dong Guo, Dawei Si, Boyuan Zhang, Baiting Tian, Fenhai Guan, Qianghua Wu, Xianglun Wei, Herun Yang, Peng Ma, Rongjiang Hu, Limin Duan, Fangfang Duan, Junbing Ma, Shiwei Xu, Qiang Hu, Zhen Bai, Yanyun Yang, Jiansong Wang, Wenbo Liu, Wanqing Su, Xiaobao Wei, Chunwang Ma, Xinxiang Li, Hongwei Wang, Yingxun Zhang, Michał Warda, Arthur Dobrowolski, Bożena Nerlo-Pomorska, Krzysztof Pomorski, Li Ou, Zhigang Xiao

Keyword:

Nuclear Experiment, Nuclear Experiment (nucl-ex), Nuclear Theory (nucl-th)

journal:

date:

2023-11-12 16:00:00

Abstract

The neutron rich neck zone created in heavy ion reaction is experimentally probed by the production of the $A=3$ isobars. The energy spectra and angular distributions of triton and $^3$He are measured with the CSHINE detector in $^{86}$Kr +$^{208}$Pb reactions at 25 MeV/u. While the energy spectrum of $^{3}$He is harder than that of triton, known as "$^{3}$He-puzzle", the yield ratio $R({\rm t/^3He})$ presents a robust rising trend with the polar angle in laboratory. Using the fission fragments to reconstruct the fission plane, the enhancement of out-plane $R({\rm t/^3He})$ is confirmed in comparison to the in-plane ratios. Transport model simulations reproduce qualitatively the experimental trends, but the quantitative agreement is not achieved. The results demonstrate that a neutron rich neck zone is formed in the reactions. Further studies are called for to understand the clustering and the isospin dynamics related to neck formation.

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