Study of the Electroweak Int. with High Energy e-p Collision

We studied the electroweak interaction in electron-proton collisions by using a multi purposedetector built in an international collaboration (ZEUS) at DESY in Germany. The unique collider HERAhigh-energy electron-proton collisonwhose maximum four momentum transfer squared (Q - D12 - D1) reaches 10 - D15 - D1 GeV - D12 - D1. Byinvestigating the neutral current (NC) interaction which is mediated by the photon and/or the Zboson as well as the charged current (CC) interaction mediated by the W boson我们could test the various aspects of the standard model.Precise measurements of the NC interactionwere performed in a wide Q - D12 - D1 range from 0.5GeV - D12 - D1 to 5000GeV - D12 - D1 in order todetermine the proton structure functions. the results were well fitted with models based with thequantum chromodynamics. Charged ciurrent cross sections were measured with data taken in the前几年The results consistent with The prediction of The standard models The mass of Wboson was extracted from the data to be consistent with that obtained by direct measurementsanalysis for the NC using full data showed an excess from the标准模型prediction in the veryhigh Q D12 D1 region. Is Is not et excluded that Is due to a statistical fluctuation but it可能会产生一种新粒子such as leptoquarks. re-analysis on the CC cross sections wasquickly performed by using the full data. Preliminary results应该在June会议1996. There was a tendency that the data above the standard model prediction，虽然它不包含在模型中的统计数据和更多的ambiguityprediction compared with the NC cross section.We need data in order to confirm the effect. HERAmachine upgrade foreseen in year 2000将给我们这个机会。

We studied the electroweak interaction in electron-proton collisions by using a multi purpose detector built in an international collaboration (ZEUS) at DESY in Germany. The unique collider HERA provides high-energy electron-proton collison, whose maximum four momentum transfer squared (QィイD12ィエD1) reaches 10ィイD15ィエD1 GeVィイD12ィエD1. By investigating the neutral current (NC) interaction which is mediated by the photon and/or the Z boson as well as the charged current (CC) interaction mediated by the W boson, we could test the various aspects of the standard model.Precise measurements of the NC interaction were performed in a wide QィイD12ィエD1 range from 0.5GeVィイD12ィエD1 to 5000GeVィイD12ィエD1 in order to determine the proton structure functions. The results were well fitted with models based with the quantum chromodynamics. Charged ciurrent cross sections were measured with data taken in the previous years. The results were consistent with the prediction of the standard models The mass of W boson was extracted from the data to be consistent with that obtained by direct measurements. The analysis for the NC using full data showed an excess from the standard model prediction in the very high QィイD12ィエD1 region. Is is not yet excluded that this is due to a statistical fluctuation but it might be an effect of new particles such as leptoquarks. re-analysis on the CC cross sections was quickly performed by using the full data. Preliminary results were shown in a conference in June 1996. There was a tendency that the data were above the standard model prediction, although it is not yet conclusive due to lack of statistics and more ambiguity in the model prediction compared with the NC cross section.We need more data in order to confirm the effect. HERA machine upgrade foreseen in year 2000 will give us this opportunity.