^(16)O具有类Hoyle结构的新证据  

New evidence of the Hoyle-like structure in^(16)O

作　　者：陈家豪 叶沿林 马凯 韩家兴 王东玺 林承键 贾会明 杨磊 李根 阳黎升 胡梓瑶 谭智威 魏康 蒲伟良 陈莹 楼建玲 杨晓菲 李奇特 杨再宏 骆天鹏 黄大湖 钟善豪 李智焕 许金艳 Jiahao Chen;Yanlin Ye;Kai Ma;Jiaxing Han;Dongxi Wang;Chengjian Lin;Huiming Jia;Lei Yang;Gen Li;Lisheng Yang;Ziyao Hu;Zhiwei Tan;Kang Wei;Wei-Liang Pu;Ying Chen;Jianling Lou;Xiaofei Yang;Qite Li;Zaihong Yang;Tianpeng Luo;Dahu Huang;Shanhao Zhong;Zhihuan Li;Jinyan Xu(School of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University,Beijing 100871,China;China Institute of Atomic Energy,Beijing 102413,China;College of Physics and Technology&Guangxi Key Laboratory of Nuclear Physics and Technology,Guangxi Normal University,Guilin 541004,China)

机构地区：[1]School of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University,Beijing 100871,China [2]China Institute of Atomic Energy,Beijing 102413,China [3]College of Physics and Technology&Guangxi Key Laboratory of Nuclear Physics and Technology,Guangxi Normal University,Guilin 541004,China

出　　处：《Science Bulletin》2023年第11期1119-1126,M0003,共9页科学通报（英文版）

基　　金：the National Key Research and Development Program of China(2018YFA0404403 and 2022YFA1602302);the National Natural Science Foundation of China(11875074,11875073,12235020,12027809,11961141003,U1967201,U2167204,11775004,and 11775003);the Continuous Basic Scientific Research Project(WDJC-2019–13);the State Key Laboratory of Nuclear Physics and Technology,Peking University(NPT2020KFY10);the Leading Innovation Project(LC192209000701 and LC202309000201)。

摘　　要：多年来的研究认为,^(12)C中位于7.65 MeV的第二个0+态,也就是通常说的Hoyle state,具有类似玻色爱因斯坦凝聚(BEC)的状态.但对于更重的核体系,如^(16)O,^(20)Ne,^(24)Mg等,尽管已有多种理论预言,但多年来对于类BEC态的实验研究尚未给出明确的结论.近期北京串列加速器国家实验室开展的非弹散射实验给出了^(16)O中存在类似4α-BEC状态的新证据.实验使用96 MeV的^(16)0束流轰击0.98μm的^(12)C靶,采用多套双面硅微条带电粒子望远镜对反应末态粒子进行探测,在^(16)O衰变中实现了4个α粒子的准确识别(PID)和符合测量.在此基础上获得了高分辨的反应Q值谱并重建了清晰的4α共振态.其中在阈值附近观察到4个高显著度(大部分高于5σ)的共振态,它们按照^(12)C(Hoyle state)+α的特征模式衰变,与理论预言的类Hoyle-BEC结构及其转动带特征相一致.本观测结果将推动进一步的理论研究,以及实验上对上述共振态做更多物理量的观测.An experiment of^(12)C(^(16)O,^(16)O→4a)^(12)C was performed at a beam energy of 96 MeV.A large number of 4-a events were recorded in coincidence and with full particle identification(PID).This was made possible by employing a series of silicon-strip-based telescopes that provided excellent position and energy resolutions.Four narrow resonances just above the 15.1 MeV state were firmly identified in the a+12C(7.65 MeV;Hoyle state)decay channel.Combined with the theoretical predictions,these resonant states provide new evidence for the predicted possible Hoyle-like structure in^(16)O above the 4-a separation threshold.Some very high-lying 4-a resonant states have also been observed and need to be further investigated.

关 键 词：带电粒子 转动带 共振态 末态粒子 特征模式 理论预言 串列加速器 符合测量 

分 类 号：O571[理学—粒子物理与原子核物理]