中国极化电子离子对撞机计划

Electron ion collider in China

轻子散射实验是探索核子与原子核结构的理想工具。中国电子离子对撞机(Electron Ion Collider in China,EicC)建议书设想在已开建的强流重离子加速器装置(High Intensity heavy ion Accelerator Facility,HIAF)的基础上,升级质子束流为20 GeV的极化束流,并建造2.8~5 GeV极化电子束流,从而实现质心系能量为15~20 GeV的双极化电子-离子对撞。EicC设计的亮度为(2~4)×10^33cm^-2·s^-1,质子束流极化率达到70%,电子束流极化率达到80%。该装置除了能提供极化轻离子束流(例如:氦-3)外,也可产生非极化重离子束流(碳-12~铀-238)。EicC将聚焦核子海夸克部分子结构、原子核物质结构与性质、奇特强子态三个方面的物理研究。高亮度、高精度的对撞机有助于精确地测量核子结构函数并对核子进行三维成像,揭示强相互作用的动力学规律;原子核部分子分布包括核子短程关联以及原子核介质效应同样是该提案的重要科学目标;EicC能区接近重味夸克产生阈值,在研究重味强子谱方面拥有低背景的独特优势,有助于发现研究新的奇特强子态。质子质量起源问题也可以通过重味矢量介子的产生来研究。为了完成上述物理目标,我们将利用最先进的探测器技术建造接近全立体角覆盖的EicC对撞机谱仪。在准备EicC白皮书的过程中,我们得到世界各国专家的支持。EicC的物理与已有的实验和美国即将建设的EIC中的物理项目相互补充。EicC的建成及运行有望引领前沿的中高能核物理研究,使我国在加速器和探测器先进技术等领域实现跨越式发展,为我国核物理与强子物理以及相关科学领域提供大型综合实验平台与人才培养基地。

Lepton scattering is an established ideal tool for studying inner structure of microscopic particles such as nucleons as well as nuclei.As a future high energy nuclear physics project,an Electron-ion collider in China(EicC)has been proposed.It will be constructed based on an upgraded heavy-ion accelerator,High intensity heavy-ion accelerator facility(HIAF)which is currently under construction,together with an additional electron ring.The proposed collider will provide highly polarized electrons(with the polarization^80%),protons and Helium-3(both with the polarization^70%),as well as unpolarized ion beams from carbon to uranium with viable center of mass energy from 15 GeV to 20 GeV and the luminosity of(2~4)×10^33cm^-2·s^-1.The main foci of the EicC will be the precision measurements of proton structure in the sea quark region,including 3 D tomography of nucleon;the partonic structure of nuclei and the parton interaction with the nuclear environment,in particular,the short range correlation of nucleons and the cold nuclear matter effects;the exotic hadronic states,especially those with heavy flavor quark contents.In addition,issues fundamental to understanding the origin of mass could be addressed by measurements of heavy quarkonia near-threshold production at the EicC.In order to achieve the above-mentioned physics goals,a hermetical detector system will be constructed with the cutting-edge technology.During preparation of the document,we have received valuable inputs and help from experts across the globe.The EicC physics program complements the ongoing scientific programs at the Jefferson Laboratory and the future EIC project in the United States.The success of this project will also advance both nuclear and hadron physics as well as accelerator and detector technology in China.CAO Xu1,2, CHANG Lei3, CHANG Ningbo4, CHEN Xurong1,2, CHEN Zhuojun5, CUI Zhufang6, DAI Lingyun5, DENGWeitian7, DING Minghui8, GONG Chang9, GUI Longcheng1,2,10, GUO Fengkun11,2 ,HAN Chengdong1,2, HE Jun12, HUANG Hongxia12, HUANG Yin13, Kaptari L P1,14, LI Demin15, LI Hengne16, LI Minxiang1,17, LI Xueqian3, LIANG Yutie1,2 ,LIANG Zuotang18, LIU Guoming16, LIU Jie12, LIU Liuming1,2, LIU Xiang17, LUO Xiaofeng19, LYU Zhun20, MABoqiang9 ,MAFu1,2, MAJianping2,11, MAYugang2,21,22, MAO Lijun1,2, Mezrag C23, PING Jialun12, QIN Sixue24, REN Hang12, Roberts C D6, SHEN Guodong1,2, SHI Chao25, SONG Qintao15, SUN Hao26, WANG Enke16, WANG Fan6, WANG Qian16, WANG Rong1,2, WANG Ruiru1,2, WANG Taofeng27 ,WANGWei28, WANG Xiaoyu15, WANG Xiaoyun29 ,WU Jiajun2, WU Xinggang24, XIAO Bowen19, XIAO Guoqing1,2, XIE Jujun1,2, XIE Yaping1,2, XING Hongxi16, XU Hushan1,2, XU Nu1,2,19, XU Shusheng30, YANWenbiao31, YANWencheng15, YAN Xinhu32, YANG Jiancheng1,2, YANG Yi-Bo2,11, YANG Zhi1,2, YAO Deliang5, YIN Peilin30, ZHANWenlong1,2, ZHANG Jianhui33, ZHANG Jinlong34, ZHANG Pengming35, CHANG Chao-Hsi2,11, ZHANG Zhenyu36, ZHAO Hongwei1,2, CHAO Kuang-Ta9, ZHAO Qiang2,37, ZHAO Yuxiang1,2, ZHAO Zhengguo31, ZHENG Liang39, ZHOU Jian18, ZHOU Xiang36, ZHOU Xiaorong31, ZOU Bingsong2,11, ZOU Liping1,2Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China;Nankai University,Tianjin 300071,China;Xinyang Normal University,Xinyang 464000,China;Hunan University,Changsha 410082,China;Nanjing University,Nanjing 210093,China;Huazhong University of Science and Technology,Wuhan 430074,China;European Centre for Theoretical Studies in Nuclear Physics and Related Areas(ECT*)and Fondazione Bruno Kessler,Villa Tambosi,Strada delle Tabarelle 286,I-38123 Villazzano(TN),Italy;School of Physics,Peking University,Beijing 100871,China;Hunan Normal University,Changsha 410081,China;CAS Key Laboratory of Theoretical Physics,Institute of Theoretical Physics,Chinese Academy of Sciences,Beijing 100190,China;Nanjing Normal University,Nanjing 210023,China;Southwest Jiaotong University,Chengdu 610000,China;Bogoliubov Laboratory of Theoretical Physics,Joint Institute for Nuclear Research,Dubna 141980,Russia;School of Physics and Engineering,Zhengzhou University,Zhengzhou 450001,China;Guangdong Provincial Key Laboratory of Nuclear Science,Institute of Quantum Matter,South China Normal University,Guangzhou 510631,China;School of Physical Science and Technology,Lanzhou University,Lanzhou 730000,China;Key Laboratory of Particle Physics and Particle Irradiation(MOE),Shandong University,Qingdao 266237,China;Key Laboratory of Quark and Lepton Physics(MOE)and Institute of Particle Physics,Central China Normal University,Wuhan 430079,China;School of Physics,Southeast University,Nanjing 211189,China;Key Laboratory of Nuclear Physics and Ion-beam Application(MOE),Institute of Modern Physics,Fudan University,Shanghai 200433,China;Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;IRFU,CEA,UniversitéParis-Saclay,F-91191 Gif-sur-Yvette,France;Department of Physics,Chongqing University,Chongqing 400044,China;Department of nuclear science and technology,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China;Dalian University of Technology,Dalian 116024,China;School of Physics,Beihang University,Beijing 100191,China;Shanghai Jiao Tong University,Shanghai 200240,China;Lanzhou University of Technology,Lanzhou 730050,China;School of Science,Nanjing University of Posts and Telecommunications,Nanjing 210023,China;University of Science and Technology of China,Hefei 230026,China;Huangshan University,Huangshan 245021,China;Center of Advanced Quantum Studies,Department of Physics,Beijing Normal University,Beijing 100875,China;Department of Physics and Astronomy,Stony Brook University,Stony Brook,NY 11794,USA;School of Physics and Astronomy,Sun Yat-sen University,Zhuhai 519082,China;School of Physics and Technology,Wuhan University,Wuhan 430072,China;Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;School of Mathematics and Physics,China University of Geosciences(Wuhan),Wuhan 430074,China)