标题： 规范统一与额外维中的味层次结构 显示英文标题

标题： Gauge Unification and Flavor Hierarchy from Extra Dimensions

摘要： 额外维度通过边界条件提供了一种吸引人的对称性破缺方式，这有助于构建自然的大统一理论，避免双态-三态分裂问题和质子衰变问题。 它还可以提供一种优雅的机制来生成四维的层级Yukawa耦合，涉及额外维度中物质场的准局部化。 我们讨论了在具有准局部化物质场的一般五维轨道空间大统一理论中，低能规范耦合的Kaluza-Klein阈值修正，并将结果应用于一些SU(5)模型在$S^1/Z_2\times Z_2$上的情况。 显示英文摘要

摘要： Extra dimension provides an attractive way to break symmetry by boundary conditions which can be useful to construct a natural grand unified theory avoiding the doublet-triplet splitting problem and the proton decay problem. It can provide also an elegant mechanism to generate hierarchical 4-dimensional Yukawa couplings, involving the quasi-localization of matter fields in extra dimension. We discuss the Kaluza-Klein threshold corrections to low energy gauge couplings in generic 5-dimensional orbifold grand unified theories with quasi-localized matter fields, and apply the results to some class of SU(5) models on $S^1/Z_2\times Z_2$.