Study of the origin of supersymmetry breaking from phenomenology and cosmology point of vieu

破缺的超对称性是解决粒子物理标准模型自然性问题的一个有希望的候选者。如果这个框架是真实的，那么揭示超对称破缺机制的本质就至关重要。本研究项目的目的是通过探索超对称破缺的各种唯象学和宇宙学意义，为寻找超对称破缺的起源提供新的见解。在低能超对称破缺的情况下，出现了一个很轻的引力子（引力子的超伴子），它可能扮演着宇宙暗物质的角色。详细研究了引力子主导宇宙中的comological结构的形成，结果表明，它并没有再现我们现在所观察到的宇宙。这个事实是轻引力子暗物质方案的一个严重困难。2.弦理论的最新发展揭示了弦理论真空结构的丰富性，激发了弦唯象学新框架的思考。例如，杂化M理论，一种描述强相互作用的杂化弦理论，可以以自然的方式解释规范耦合的统一。受这些发展的启发，我们研究了超对称性破缺的细节通过gaugino凝聚方案和澄清的异同的性质的超对称性破缺以及超粒子的质谱，在comarison与传统的弱耦合制度。除了上述结果，我们还得到了一些有趣的结果，例如，当与超对称破缺的各种机制相结合时，轴子物理。

Broken supersymmetry has been a promising canditate for solving the naturalness problem of the standard model of particle physics. If this framework is real, it is crucially important to reveal the nature of the mechanism of supersymmetry breaking. The purpose of this research project is to obtain new insights on the search of the origin of the super-symmetry breaking by exploring various phenomenological and cosmological implications associated with the supersymmetry breaking.Among other things, the most notable results are 1. in the low-energy supersymemtry breaking scenario, there appears a very light gravitino (the superpartner of graviton) which may play a role of the dark matter of the universe. A detailed study of the comological structure formation in the gravitino dominated universe was done, and it shows that it does not reproduce the universe we observe now. This fact is a severe difficulty of the light gravitino dark matter scenario. 2. Recent developments of string theory have revealed the richenss of the vacuum structure of the string theory, which has stimulated to consider new frameworks of string phenomenology. For example the heterotic M-theory, a description of strongly interacting heterotic string theory, can explain the unification of gauge couplings in a natural way. Motivated by these developments, we investigated details of the supersymmetry breaking via the gaugino condensation scenario and clarified similarities and differences on the nature of the supersymmetry breaking as well as the superparticl mass spectra, in comarison with the conventional weak coupling regime. In addition to the results above, we obtained, for example, interesting results on axion physics when combined with various mechanisms of the sup ersymmetry breaking.