Observing the ping-pong modality of the isospin degree of freedom in cluster emission from heavy-ion reactions
Yijie Wang, Fenhai Guan, Xinyue Diao, Mengting Wan, Yuhao Qin, Z. Qin, Qianghua Wu, Dong Guo, Dawei Si, Sheng Xiao, Boyuan Zhang, Yaopeng Zhang, Baiting Tian, Xianglun Wei, Herun Yang, Peng Ma, Rongjiang Hu, Limin Duan, Fangfang Duan, Qiang Hu, Junbing Ma, Shiwei Xu, Zhen Bai, Y. Y. Yang, J. Wang, Wenbo Liu, Wanqing Su, Xiaobao Wei, Chun-Wang Ma, Xinxiang Li, Hongwei Wang, Fangyuan Wang, Yingxun Zhang, M. Warda, Arthur Dobrowolski, B. Nerlo-Pomorska, K. Pomorski, Li Ou, Zhigang Xiao
Abstract
Thermodynamic and chemical two-body correlations of the isotope-resolved clusters are measured in $^{86}\mathrm{Kr}+^{208}\mathrm{Pb}\phantom{\rule{4pt}{0ex}}$reactions at 25 MeV/u. The yield and kinetic variables of the $A=3$ isobars are analyzed in coincidence with the intermediate mass fragments of $6\ensuremath{\le}A\ensuremath{\le}11$. While the velocity spectra of both $t$ and $^{3}\mathrm{He}$ exhibit scaling behavior over the type of the intermediate mass fragments, the yield ratios of $t/^{3}\mathrm{He}$ correlate reversely to the neutron-to-proton ratio $N/Z$ of the latter, showing the ping-pong modality of the $N/Z$ of the emitted particles. The commonality that the $N/Z$ of the residues keeps the initial system value is extended to the cluster emission in heavy ion reactions. The comparison to transport model calculations to the data is discussed.