Symmetry breaking and effecto of heavy particles in electro-weak gauge theories

基于SU（3）× SU（2）_L × U（1）群的规范理论与电-弱相互作用中的各种测量有很好的雅阁（有一定的不确定性）。为了使该模型成为强相互作用和电-弱相互作用的统一理论，对该理论中的辐射修正进行精确检验是至关重要的。本研究计划的目的是：a）研究能量E高于弱玻色子质量标度M_W的物理规律，特别是轻粒子过程中可能的重粒子通过辐射修正的影响。B）研究旨在理解Higgs粒子的性质。c）确定夸克和轻子性质的唯象研究。针对a）和c）的目的，我们研究了规范玻色子两点和三点耦合中重粒子的非退耦效应，得到了一些有趣的结果（如报告《电-弱参数和新物理学的精确测试》中所总结的）：1）分析了S，T，两点函数的U参数有助于理解斜校正。2）与S和T的精确测量比较，给出了额外世代数N_的有意义的上限<eg>。3）关于三重规范玻色子耦合，我们已经确定了四个参数，它们足以描述在γ W ^+W^-和Z^OW^+W_-中重粒子的非去耦效应。至于目的B），我们已经在理论中研究了希格斯玻色子的性质，在理论中，希格斯玻色子在时空的额外维度中具有几何作用。这方面的研究仍在进行中。

The gauge theory based on the group SU(3) X SU(2)_L X U(1) is in good accord (with some uncertainty) with various kinds of measurements in electro-weak interactions. For this model to be established as the unified theory of strong and electro-weak interactions, it is crucial to make precision testy of radiative corrections in this theory. The purposes of the present research project are the following :a) To study the physics law at energies E higher than the weak-boson mass scale M_W, in particular, the effects of possible heavy particles through radiative corrections in light particle processes.b) Research aiming at understanding the nature of the Higgs particle.c) Phenomenological study to determine the properties of quarks and leptons.Regarding the purposes a) and c) we have studied the non-decoupling effects of heavy particles in the gauge boson two- and three-point couplings and have obtained a few interesting results (as summarized in the report "Precision Test of Electro-Weak Parameters and New Physics" ) :1) The analysis of the symmetry properties of the S, T, U parameters of the two-point functions is useful in understanding the oblique corrections.2) Comparison with the precision measurements of S and T gives a meaningful upper bound on the number of extra generations N_<eg>.3) Regarding the triple gauge-boson couplings, we have identified the four parameters which are sufficient to describe the non-decoupling effects of heavy particles in the gammaW^+W^- and Z^OW^+W_- couplings.As for the purpose b), we have studied the properties of the Higgs in theories in which it is given a geometrical role in extra dimensions of space-time. The research in this direction is still in progress.