Radiative Corrections to Boson Pair-Production in Electron-Positron Collisions

本研究项目的主要目标是基于标准模型，如果可能的话，基于超对称模型，计算电子-正电子碰撞中四费米子产生的辐射修正。在LEP-II实验中，计算对于精确理解W-物理是必不可少的，在本项目中，我们取得了以下成果：计算了W的单圈辐射修正和两个费米子的产生。虽然该过程比目标过程简单，但这项工作有两个分支：第一，它可以检查自动化系统的功能。第二，但更重要的一点是，它使我们能够估计的差异，从计算的基础上因式分解。我们发现与因式分解的结果有1-2%的偏差，因此为了充分理解W对的产生，需要进行完整的单循环计算。此外，在本项目中，我们引入了自动化系统，这是一种新的机制来检查大规模计算。广义非线性规范的使用被用作有用的诊断。通过对各种二对二过程的显式计算证明了这种检查的有效性。不幸的是，最后一个项目，一个实际事件发生器的开发，尚未在项目期限内完成。预计将在一年内结束。

The main goal of this research project is to calculate the radiative corrections to the four-fermion production in electron-positron collisions based on the standard model and, if possible, on the supersymmetric models. The calculation is essential for the precise understanding of W-physics in the LEP-II experiments.In this project, we have achieved the followings.We computed the one-loop radiative correction to W and two fermions production. Though the process is simpler than the target process, this work has two off-springs : First, it can check the function of automated systems. Second but more important point is that it enables us to estimate the discrepancy from the computation based on the factorization. We found 1-2% deviation from the factorized results, so that the full one-loop calculation is necessary for the full understanding of the W pair production.Also, in this project, we have introduced the automated system a new mechanism to check the large-scale computation. The use of generalized non-linear gauge is used as a useful diagnostics. The validity of this check is demonstrated through the explicit computation for various two-to-two processes.Unfortunately, the final item, the development of a practical event generator, is not yet finished within the term of the project. It is expected that it will be end within a year.