Electron-ion collider in China
Authors: Anderle Daniele P. , Bertone Valerio , Cao Xu , Chang Lei , Chang Ningbo , Chen Gu , Chen Xurong , Chen Zhuojun , Cui Zhufang , Dai Lingyun , Deng Weitian , Ding Minghui , Feng Xu , Gong Chang , Gui Longcheng , Guo Feng-Kun , Han Chengdong , He Jun , Hou Tie-Jiun , Huang Hongxia , Huang Yin , KumeričKi KrešImir , Kaptari L. P. , Li Demin , Li Hengne , Li Minxiang , Li Xueqian , Liang Yutie , Liang Zuotang , Liu Chen , Liu Chuan , Liu Guoming , Liu Jie , Liu Liuming , Liu Xiang , Liu Tianbo , Luo Xiaofeng , Lyu Zhun , Ma Boqiang , Ma Fu , Ma Jianping , Ma Yugang , Mao Lijun , Mezrag Cédric , Moutarde Hervé , Ping Jialun , Qin Sixue , Ren Hang , Roberts Craig D. , Rojo Juan , Shen Guodong , Shi Chao , Song Qintao , Sun Hao , Sznajder Paweł , Wang Enke , Wang Fan , Wang Qian , Wang Rong , Wang Ruiru , Wang Taofeng , Wang Wei , Wang Xiaoyu , Wang Xiaoyun , Wu Jiajun , Wu Xinggang , Xia Lei , Xiao Bowen , Xiao Guoqing , Xie Ju-Jun , Xie Yaping , Xing Hongxi , Xu Hushan , Xu Nu , Xu Shusheng , Yan Mengshi , Yan Wenbiao , Yan Wencheng , Yan Xinhu , Yang Jiancheng , Yang Yi-Bo , Yang Zhi , Yao Deliang , Ye Zhihong , Yin Peilin , Yuan C.-P. , Zhan Wenlong , Zhang Jianhui , Zhang Jinlong , Zhang Pengming , Zhang Yifei , Chang Chao-Hsi , Zhang Zhenyu , Zhao Hongwei , Chao Kuang-Ta , Zhao Qiang , Zhao Yuxiang , Zhao Zhengguo , Zheng Liang , Zhou Jian , Zhou Xiang , Zhou Xiaorong , Zou Bingsong , Zou Liping 
Published: June 2021

Lepton scattering is an established ideal tool for studying inner structure of small 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 a new electron ring. The proposed collider will provide highly polarized electrons (with a polarization of ∼80%) and protons (with a polarization of ∼70%) with variable center of mass energies from 15 to 20 GeV and the luminosity of (2–3) × 1033 cm−2 · s−1. Polarized deuterons and Helium-3, as well as unpolarized ion beams from Carbon to Uranium, will be also available at the EicC.

The main foci of the EicC will be precision measurements of the structure of the nucleon in the sea quark region, including 3D tomography of nucleon; the partonic structure of nuclei and the parton interaction with the nuclear environment; the exotic 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 cutting-edge technologies.

This document is the result of collective contributions and valuable inputs 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 particle physics as well as accelerator and detector technology in China.