Experimental Study of Elementary Particle Physics by the Electron-Proton Collider HERA

这项研究计划的目的是通过在HERA建造的第一台e-p对撞机上的电子-质子碰撞来研究基本粒子物理学。对撞机的质心能量为314GeV，这使得能够打开这样的新领域来研究非常大的Q^2和/或很小的x区域的质子结构函数，或者澄清在很短距离内的电弱相互作用的详细性质。除其他外，这些研究需要一个高质量的复杂探测器系统，该系统可以密闭地探测不同类型的二次粒子。该计划集中在过去三年内建造了一个万能探测器宙斯，以满足这一要求。活动包括：1)建造高质量的强子量热计系统，2)研发使用硅二极管阵列的电子-强子分离器，3)开发和建造全球第一能级触发系统，4)建立模拟软件和研究触发第二…更多的是利用模拟事件。描述了每个项目的一些细节和成果。1)热量基础研发工作是在这个项目之前完成的。在这个项目中，我们致力于构建量热计。到目前为止，前部和后部的量热仪已经全部完成测试并安装到实验大厅中。用计算机控制的测试系统对光电倍增管进行了测试，并提出了一种给光电倍增管提供高压的新方案。3)GFL为了应对高冲突率(10 MHz)，采用了管道衬里设计，以便有足够长的计算时间(5Musec)用于触发决策。系统已经建成，与探测器部件的通信测试正在进行中。到目前为止，用一些组件进行的测试被证明是成功的。4)模拟正在准备一个简化的软件来模拟物理反应和探测器的响应。它们被安装到INS的计算机系统中，在那里有大量的CPU时间可用。深度非弹性散射事件(中性电流和带电电流)和背景事件都是与其他机构合作产生的。他们被用来研究触发条件，以有效地消除束气本底。所有活动都是在与外国合作者密切合作的情况下进行的。由于许多工作都是在国内进行的，因此，为了统一在不同机构取得的成就，在实验地点进行讨论和共同努力是必不可少的。较少

The purpose of this research program is to study elementary particle physics by means of electron-proton collisions at HERA, the first e-p collider ever built. The center of mass energy of the collider is 314 GeV, which enables to open such new fields to investigate the proton structure functions at very large Q^2 and/or very small x regions or to clarify the detailed properties of electro-weak interactions at very short distances. These studies require among others a high quality sophisticated detector system which can detect different types of secondary particles in a hermetic way. This program concentrated for the last three years to build an universal detector ZEUS to fulfill the requirement. Activities included ;1) Construction of a high quality hadron calorimeter system, 2) R&D of an electron-hadron separator using a Si-diode array, 3) Development and construction of a global first level trigger (GFLT) system and 4) Establishment of simulation software and studies of trigger cond … More itions using simulated events.Some details and achievements are described for each item.1) CalorimeterBasic R&D works were finished before this program. In this program efforts are made to construct calorimeters. By now all forward and rear calorimeters have been completed, tested and installed into the experimental hall. Photomultipliers were tested with a computer controlled test system and a new scheme was developed to supply high voltage to them.2) Hadron-Electron SeparatorAll the basic studies have been completed for the detector, mechanics and electronics. Tests were made with a small detector sample inserted in the prototype calorimeter.3) GFLTIn order to cope with the high rate of collisions (10MHz), a pipe-lined design was employed so that a long enough computation time (5 musec) is available for trigger decisions. The system has been constructed and the tests of communication with the detector components are progressing. The test made so far with some components proved to be successful.4) SimulationsElaborated software are being prepared to simulate physics reactions and detector responses. They were installed into the computer system of INS, where a substantial cpu time is available. Both deep inelastic scattering events (neutral current and charged current) and background events were produced in collaboration with other institutions. They were used to study trigger conditions to eliminate the beam-gas background effectively.All activities were carried out in a close collaboration with the foreign collaborators. Since much work were made at home, discussions and combined efforts at the experimental cite were essential in order to unify the accomplishments made at different institutions. Less