Study of e-p collisions by the ZUES international collaboration

在德国DESY建造的e-p对撞机HERA上，利用ZEUS国际合作研究了基本粒子及其相互作用。合作研制了具有超导螺线管线圈的通用型ZEUS探测器。主要的探测器组成部分，包括高分辨率量热计、中央跟踪室和介子室系统在1991财政年度内完成。在进入进入区域后，探测器用宇宙射线进行了数据采集测试。1992年5月至6月，HERA首次运行物理。对不同来源的背景进行调查，以便在触发水平上尽可能多地拒绝背景，以便有效地进行数据采集。利用光束计数器和量热计的时间信息成功地完成了这一工作。在初夏和秋季进行了两次数据采集，820 GeV质子和26.6 GeV电子。累积的总发光量约为30 nb^<-1>。对中性电流深非弹性散射和光产生进行了初步分析。高质心能量允许在运动学区域研究这些反应，这在以前是不可接近的。例如，在210 GeV下测量了光子-质子反应的总横截面，比现有数据高出一个数量级。它显示出轻微的增长，但不是根据一些宇宙射线现象推测的快速增长。深度非弹性散射的研究提供了在非常小的尺度变量x下质子结构函数的新信息，而目前的技术无法计算量子cd。动量传递Q^2大幅增加，达到10^4 GeV/c^2。到目前为止，在高Q^2区域还没有观察到像峰一样的特殊结构，如果产生一种叫做轻夸克的奇异粒子，就会出现这种结构。对不同情况下的质量极限进行了估计。少

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