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

破缺超对称已成为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是至关重要的。本研究项目的目的是通过探索与超对称破缺相关的各种现象学和宇宙学含义，为寻找超对称破缺的起源获得新的见解。在其他方面，最显著的结果是1。在低能超对称破缺情景中，出现了一种非常轻的引力子（引力子的超级伴侣），它可能扮演着宇宙暗物质的角色。对引力子主导的宇宙的宇宙学结构形成进行了详细的研究，结果表明它并不能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场景的一个严重困难。2. 弦理论的最新发展揭示了弦理论真空结构的丰富性，这刺激了对弦现象学新框架的思考。例如，描述强相互作用的异质性弦理论的异质性m理论，可以很自然地解释规范耦合的统一。在这些发展的推动下，我们通过高介子凝聚场景研究了超对称破缺的细节，并澄清了超对称破缺性质以及超粒子质量谱与传统弱耦合机制的异同。除了上述结果之外，我们还获得了一些有趣的结果，例如，当结合超对称破缺的各种机制时，轴子物理学的结果。

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.