Study of e-p collisions by the ZUES international collaboration

ZUES 国际合作研究 e-p 碰撞

• 批准号: 03044033
• 负责人: YAMADA Sakue
• 金额: $ 13.12万
• 依托单位: Institute for Nuclear Study, Univ. of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03044033/
• 关键词: HERA; ZEUS; Electron-proton scattering; Deep inelastic scattering; Structure function; Leptoquark; QCD; Photoproduction; パイプライン方式トリガ-; 半導体検出器; ハドロン電子分散器; ビ-ム衝突; 電子陽子衝突; 励起電子; レプトクォ-ク

Elementary Particles and their interactions are studied with the ZEUS international collaboration at the e-p collider HERA built at DESY, Germany.The universal purpose ZEUS detector with a superconductive solenoid coil was constructed by the collaboration. Major detector components including high resolution calorimeters, a central tracking chamber and muon chamber system were completed within the fiscal year 1991. After being rolled in into the enteraction region, the detector was tested with cosmic rays for data taking.From May to June, 1992, HERA was operated for physics for the first time. Investigation of backgrounds from various origins was started in order to reject as much background as possible at trigger level so that data taking be made efficiently. This was done successfully by means of time information from a beam counter and the calorimeters. Data taking was made twice, in early summer and autumn, with 820 GeV protons and 26.6 GeV electrons. In total an integrated luminosi … More ty of about 30 nb^<-1> was accumulated.Initial analyses of the neutral-current deep inelastic scattering and photoproductions were performed. The high center of mass energy allowed to study these reactions in the kinematical regions which had previously been inaccessible. For instance the total cross section of the photon-proton reaction was measured at 210 GeV, which is one order of magnitude higher than that of the existing data. It showed a slight increase but not a rapid rise as speculated based on some cosmic ray phenomena.Studies of the deep inelastic scattering provided new information on the proton structure function at very small scaling variable, x,where QCD can't be calculated in the present technique. The momentum transfer Q^2 was increased substantially reaching 10^4 GeV/c^2. So far no particular structure like a peak, which is expected if an exotic particle called leptoquark is produced, has been observed in the high Q^2 region. Limits on the masses for different cases were estimated. Less

在德国DESY建造的e-p对撞机HERA上，与Zeus国际合作研究了基本粒子及其相互作用，并通过合作构建了具有超导螺线管线圈的通用Zeus探测器。主要探测器部件，包括高分辨率热量计、中央跟踪室和Muon室系统，已在1991财政年度内完成。在进入进入对撞区后，探测器进行了宇宙射线测试以获取数据。1992年5月至6月，HERA首次用于物理操作。开始对不同来源的背景进行调查，以便在触发水平上尽可能排除更多的背景，以便有效地获取数据。这是通过来自束流计数器和量热计的时间信息成功地完成的。数据采集进行了两次，分别是在初夏和秋季，采集了820个GeV质子和26.6 GeV电子。总而言之，集成了LIGHTOSI…积累了约30nb~(-1)~(-1)的Ty，并对中性流深度非弹性散射和光生进行了初步分析。高质量中心的能量允许在运动学区域研究这些反应，而这些区域以前是无法到达的。例如，光子-质子反应的总截面测量为210GeV，比现有数据高一个数量级。对深部非弹性散射的研究提供了关于极小标度变量x的质子结构函数的新信息，其中QCD不能用目前的技术计算。动量传递Q^2大大增加，达到10^4GeV/c^2。到目前为止，在高Q^2区还没有观察到像峰这样的特殊结构，如果产生一种称为轻夸克的奇异粒子，就会出现这种结构。估算了不同情况下的人群限值。较少

项目成果

ZEUS Collaboration ; M.Derrick et al.: "Initial Study of Deep Inelastic Scattering with ZEUS at HERA" Physics Letters B. 297. 404-416 (1992)

宙斯合作；

ZEUS Collaboration;M.Derrick et al: "A Measurement of σ_<+0+>(δP) at √<S>=210GeV" Physics Letters B. 293. 465-477 (1992)

ZEUS 协作；M.Derrick 等人：“在 √<S>=210GeV 处测量 σ_<+0+>(δP)”《物理快报》B. 293. 465-477 (1992)