New Physics Search via Radiative Corrections

众所周知，基于SU (2) * U(1)规范群的标准电弱理论成功地描述了各种弱相互作用过程，迄今为止我们还没有可靠的数据需要对该理论进行任何修正或推广。然而，从理论的角度来看，经常有人指出，这一理论不会是“最终理论”。辐射修正是超越这一标准理论的新物理学的一个重要而有效的窗口。这是因为即使是在实际实验中无法产生的非常重的粒子也会像量子效应一样影响物理观察。另一方面，我们期望在未来的加速器如NLC/LHC上直接产生新的粒子/现象。在本研究中，我们不仅研究了作为纯环路效应的辐射修正，还研究了通过辐射修正可能引起的非标准相互作用，研究了在NLC中从相对低能的B/ d强子衰变到高能顶夸克对的产生。一个显著的结果是对电弱辐射修正的结构的分析。在那里，我们发现最新的W/Z质量数据强烈表明通过重顶环存在非解耦效应。这将成为标准理论之外的各种新物理模型的强大约束。

It is well-known that various weak-interaction processes are successfully described by the standard electroweak theory, which is based on SU (2) * U (1) gauge group, and we have so far no reliable data which require any corrections or extention of this theory. From theoretical point of view, however, it is often pointed out that this theory will not be the "final theory". Radiative corrections are an important and effective window on new physics beyond this standard theory. This is because even very heavy particles which cannot be produced in actual experiments can affect physical observables as the quantum effects. On the other hand, we expect direct productions of new particles/phenomena at future accelerators like NLC/LHC.In this research, we aimed to investigate not only radiative corrections as pure loop effects but also nonstandard interactions which may be induced via radiative corrections, studying from relatively-low-energy B/D-hadron decays to high-energy top-quark pair productions at NLC.A remarkable result is an analysis of the structure of the electroweak radiative corrections. There, we found that the latest data of W/Z masses strongly indicate the existence of the nondecoupling effects via the heavy top loops. This will be a strong constraint on various models of new physics beyond the standard theory.