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2...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。展开更多
The property of σ-meson or f0(400-1200)is studied in the general color symmetry model(GCM)for quantum chromodynamics.With recent determined values of mσ,fσand fπin GCM,the isoscalarππS-wave amplitude is calculat...The property of σ-meson or f0(400-1200)is studied in the general color symmetry model(GCM)for quantum chromodynamics.With recent determined values of mσ,fσand fπin GCM,the isoscalarππS-wave amplitude is calculated without any free parameter.The T-matrix pole for f0(400-1200)is found to be 1011-i 284MeV,which is very close to the Particle Data Group value(400-1200)-i(300-500)MeV.展开更多
We discuss the X(5568)particle recently announced by the D0 Collaboration.Several types of models were proposed to explain this structure in the literature.As pointed out by Burns and Swanson(ar Xiv:1603.04366),none o...We discuss the X(5568)particle recently announced by the D0 Collaboration.Several types of models were proposed to explain this structure in the literature.As pointed out by Burns and Swanson(ar Xiv:1603.04366),none of them provides a satisfactory description of the observation.We provide additional arguments using general properties of QCD,and conclude that the observation of the X(5568),if confirmed,poses serious challenges to our understanding of nonperturbative QCD.展开更多
The pp → nK^＋E^＋ reaction is a very good isospin 3/2 filter for studying △^＋＋＊ decaying to K^＋E^＋. The proton beam experiment with a scheduled 4π hadron detector at Lanzhou Cooler Storage Ring （CSR） will m...The pp → nK^＋E^＋ reaction is a very good isospin 3/2 filter for studying △^＋＋＊ decaying to K^＋E^＋. The proton beam experiment with a scheduled 4π hadron detector at Lanzhou Cooler Storage Ring （CSR） will make the study of this reaction possible. Here, based on very limited available knowledge on the relevant ingredients for this reaction, we give theoretical prediction with Monte Carlo simulation for various observables for this reaction. This could serve as a reference for building the scheduled hadron detector and for identifying new physics in the following-on experiments at CSR.展开更多
The quest for understanding the internal structure of hadrons is key to probing how color confinement,which remains a fundamental challenge in the Standard Model,manifests itself.The lowest-lying hadrons fit well into...The quest for understanding the internal structure of hadrons is key to probing how color confinement,which remains a fundamental challenge in the Standard Model,manifests itself.The lowest-lying hadrons fit well into the classification of the conventional quark model,such as quark-antiquark mesons and three-quark baryons.However,for excited states,the energy excitation inside a hadron can be distributed in various ways:it can appear as orbital or radial excitation within a conventional quark model configuration,or it leads to the creation of a quark-antiquark pair.展开更多
文摘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。
基金supported in part by the Chinese Academy of Sciences(CAS)under Grant No.XDB34030000 and No.QYZDBSSW-SYS013the National Natural Science Foundation of China(NSFC)under Grant No.11835015,No.12047503 and No.11961141012+1 种基金the NSFC and the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)through the funds provided to the Sino-German Collaborative Research Center TRR110"Symmetries and the Emergence of Structure in QCD"(NSFC Grant No.12070131001,DFG Project-ID 196253076)the CAS Center for Excellence in Particle Physics(CCEPP).
基金Supported by the National Natural Science Foundation of China under Grant Nos.19335022 and 19675057the China Post-doctoral Science Foundation+1 种基金the Grant LWTZ 1298 of the Academy of Sciencesthe K.C.Wong Education Foundation.
文摘The property of σ-meson or f0(400-1200)is studied in the general color symmetry model(GCM)for quantum chromodynamics.With recent determined values of mσ,fσand fπin GCM,the isoscalarππS-wave amplitude is calculated without any free parameter.The T-matrix pole for f0(400-1200)is found to be 1011-i 284MeV,which is very close to the Particle Data Group value(400-1200)-i(300-500)MeV.
基金Supported by DFG and National Natural Science Foundation of China Through Funds Provided to the Sino-German CRC 110"Symmetriesthe Emergence of Structure in QCD"(National Natural Science Foundation of China under Grant No.11261130311)+1 种基金the Thousand Talents Plan for Young Professionalsand the Chinese Academy of Sciences President’s International Fellowship Initiative under Grant No.2015VMA076
文摘We discuss the X(5568)particle recently announced by the D0 Collaboration.Several types of models were proposed to explain this structure in the literature.As pointed out by Burns and Swanson(ar Xiv:1603.04366),none of them provides a satisfactory description of the observation.We provide additional arguments using general properties of QCD,and conclude that the observation of the X(5568),if confirmed,poses serious challenges to our understanding of nonperturbative QCD.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10225525 and 10435080, and the Knowledge Innovation Project of the Chinese Academy of Sciences under Grant No KJCX2-SW-N02.
文摘The pp → nK^＋E^＋ reaction is a very good isospin 3/2 filter for studying △^＋＋＊ decaying to K^＋E^＋. The proton beam experiment with a scheduled 4π hadron detector at Lanzhou Cooler Storage Ring （CSR） will make the study of this reaction possible. Here, based on very limited available knowledge on the relevant ingredients for this reaction, we give theoretical prediction with Monte Carlo simulation for various observables for this reaction. This could serve as a reference for building the scheduled hadron detector and for identifying new physics in the following-on experiments at CSR.
基金supported in part by the National Natural Science Foundation of China(12125507,12361141819,and 12447101)the National Key R&D Program of China(2023YFA1606703)the Chinese Academy of Sciences(YSBR101).
文摘The quest for understanding the internal structure of hadrons is key to probing how color confinement,which remains a fundamental challenge in the Standard Model,manifests itself.The lowest-lying hadrons fit well into the classification of the conventional quark model,such as quark-antiquark mesons and three-quark baryons.However,for excited states,the energy excitation inside a hadron can be distributed in various ways:it can appear as orbital or radial excitation within a conventional quark model configuration,or it leads to the creation of a quark-antiquark pair.
