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 top triangle moose （TTM） model, which can be seen as the deconstructed version of the topcolor- assisted technicolor （TC2） model, predicts the existence of the charged top-pious πt± in low energy spectru...The top triangle moose （TTM） model, which can be seen as the deconstructed version of the topcolor- assisted technicolor （TC2） model, predicts the existence of the charged top-pious πt± in low energy spectrum. In the context of this model, we consider photoproduction of πt± via the subprocesses γb→tπt- and γb -tπt＋ at the large hadron-electron eollider （LHeC）, in which high energy photon beams are generated by using the Compton backscatting method. We find that, as long as the charged top-pious are not too heavy, they can be abundantly produced via γb collision.展开更多
Using data samples collected at center-of-mass energies of √s=4.009, 4.230, 4.260, and 4.360 GeV with the BES0 detector operating at the BEPC/ collider, we perform a search for the process e＋e-→γχc,j （J =0, 1, 2...Using data samples collected at center-of-mass energies of √s=4.009, 4.230, 4.260, and 4.360 GeV with the BES0 detector operating at the BEPC/ collider, we perform a search for the process e＋e-→γχc,j （J =0, 1, 2） and find evidence for e＋e-→γχc1 and e＋e-→γχc2 with statistical significances of 3.0σ and 3.4σ, respectively. The Born cross sections σB（e＋e-→γχc,j）, as well as their upper limits at the 90% con dence level （C.L.） are determined at each center-of-mass energy.展开更多
We discuss the shape of threshold signals in production cross sections of the reaction e＋e- → D＊ Dˉ＊, at the opening of the Ds＊ Dˉs＊ and Λc＋ Λ＋c channels. Furthermore, evidence for the ψ（3D）, ψ（5S）,...We discuss the shape of threshold signals in production cross sections of the reaction e＋e- → D＊ Dˉ＊, at the opening of the Ds＊ Dˉs＊ and Λc＋ Λ＋c channels. Furthermore, evidence for the ψ（3D）, ψ（5S）, ψ（4D）, ψ（6S）, ψ（5D）, ψ（7S）, ψ（6D）, and ψ（8S） new charmonium vector resonances is presented, on the basis of data recently published by the BABAR Collaboration. Central masses and resonance widths are estimated. Confirmation of these resonances would be a huge step in lifting the precision level of hadron spectroscopy towards that of atomic spectroscopy, with far-reaching consequences for theory.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 Russian Education and Science Ministry(RFMEFI61014X0002)Russian Foundation for Basic Research(RFBR 13-02-00991-a,RFBR 13-02-00215-a,RFBR12-02-01032-a,RFBR 13-02-01134-a,RFBR 14-02-00580-a,RFBR 14-02-31275-mol-a,RFBR 14-02-00047-a,RFBR 14-02-31478-mol-a,RFBR 14-02-91332 and the DFG grant HA 1457/9-1)
基金Supported by the Russian Science Foundation(14-50-00080)Russian Foundation for Basic Research(13-02-00215-a+6 种基金13-02-01134-a14-02-00580-a14-02-31275-mol-a14-02-00047-a14-02-31478-mol-a14-02-9133215-02-05674)
基金Supported in part by the National Natural Science Foundation of China under Grant No.10975067the Natural Science Foundation of the Liaoning Scientific Committee under Grant No.201102114Foundation of Liaoning Educational Committee under Grant No.LT2011015
文摘The top triangle moose （TTM） model, which can be seen as the deconstructed version of the topcolor- assisted technicolor （TC2） model, predicts the existence of the charged top-pious πt± in low energy spectrum. In the context of this model, we consider photoproduction of πt± via the subprocesses γb→tπt- and γb -tπt＋ at the large hadron-electron eollider （LHeC）, in which high energy photon beams are generated by using the Compton backscatting method. We find that, as long as the charged top-pious are not too heavy, they can be abundantly produced via γb collision.
基金Supported by National Key Basic Research Program of China(2015CB856700)Joint Funds of National Natural Science Foundation of China(11079008,11179007,U1232201,U1332201,U1232107)+7 种基金National Natural Science Foundation of China(NSFC)(10935007,11121092,11125525,11235011,11322544,11335008)Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Program,CAS(KJCX2-YW-N29,KJCX2-YW-N45)100 Talents Program of CAS,INPAC and Shanghai Key Laboratory for Particle Physics and CosmologyGerman Research Foundation DFG(Collaborative Research Center CRC-1044)Istituto Nazionale di Fisica Nucleare,Italy,Ministry of Development of Turkey(DPT2006K-120470)Russian Foundation for Basic Research(14-07-91152)U.S.Department of Energy(DE-FG02-04ER41291,DE-FG02-05ER41374,DE-FG02-94ER40823,DESC0010118)U.S.National Science Foundation,University of Groningen(RuG)and Helmholtzzentrum fuer Schwerionenforschung GmbH(GSI),Darmstadt,WCU Program of National Research Foundation of Korea(R32-2008-000-10155-0)
文摘Using data samples collected at center-of-mass energies of √s=4.009, 4.230, 4.260, and 4.360 GeV with the BES0 detector operating at the BEPC/ collider, we perform a search for the process e＋e-→γχc,j （J =0, 1, 2） and find evidence for e＋e-→γχc1 and e＋e-→γχc2 with statistical significances of 3.0σ and 3.4σ, respectively. The Born cross sections σB（e＋e-→γχc,j）, as well as their upper limits at the 90% con dence level （C.L.） are determined at each center-of-mass energy.
文摘We discuss the shape of threshold signals in production cross sections of the reaction e＋e- → D＊ Dˉ＊, at the opening of the Ds＊ Dˉs＊ and Λc＋ Λ＋c channels. Furthermore, evidence for the ψ（3D）, ψ（5S）, ψ（4D）, ψ（6S）, ψ（5D）, ψ（7S）, ψ（6D）, and ψ（8S） new charmonium vector resonances is presented, on the basis of data recently published by the BABAR Collaboration. Central masses and resonance widths are estimated. Confirmation of these resonances would be a huge step in lifting the precision level of hadron spectroscopy towards that of atomic spectroscopy, with far-reaching consequences for theory.
