วิทยานิพนธ์ (วท.ม.)--จุฬาลงกรณ์มหาวิทยาลัย, 2550

The Little Hierarchy problem refers to the conflicts between the results from precision electroweak experiments, which require new physics beyond the standard model above 10TeV scale, and the condition that the Higgs particle in the standard model is naturally light without extreme fine-tunings on some parameters, which, on the other hand, requires new physics below 2TeV. Recently, a new class of models called Little Higgs was proposed to solve the problem while only few review articles were available. This thesis provides rudiments of the Little Higgs and relevant topics that are useful for understanding physics beyond the standard model; including the hierarchy problem, dynamical symmetry breaking, vacuum alignment, non-linear realisations of a symmetry, and grand unification theory. Detail inspections on most economical model known as the Littlest Higgs along with some phenomenological signatures allowing distinction from other models which are testable in next generation particle colliders, such as the Large Hadron Collider (LHC) at CERN, are considered. It was found that this Littlest Higgs does not fully eliminate the little hierarchy problem.