Search for the Supersymmetric Models through the Universe with Dark Matter

2015 Fiscal Year Final Research Report

• Project/Area Number: 24740145
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Utsunomiya University (2013-2015); Saitama University (2012)
• Principal Investigator: Koike Masafumi 宇都宮大学, 工学(系)研究科(研究院), 准教授 (10447279)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 暗黒物質 / 超対称模型 / 標準模型をこえる物理 / ビッグバン元素合成 / リチウム問題 / レプトンフレーバー

Outline of Final Research Achievements

We searched for the models beyond the Standard Model that resolve the following two major cosmological problems: (1) the abundance of the dark matter in the universe, and (2) the possible deficit of the abundance of premordial lithium. We also put the constraint on the mass of Higgs particle to be 125 GeV. Our scenario is build around the next-to-minimal supersymmetric standard model. The next-to-lightest supersymmetric particles (NLSP) interact with the lithium nuclei during the nucleosynthesis and destroy part of them. The NLSP's eventually decay to the lightest supersymmetric particles, left as the stable dark matter to date. Varying the values of model parameters, we simulated the reactions of the particles and nuclei during the nucleosynthesis and calculated the relic abundance of the lithium and the dark matter. We showed the parameter region that is consistent with all the phenomenological constraints, and thereby proved that our senario is indeed viable.

Free Research Field

素粒子物理学