Exploring light dark matter through long-lived particle searches

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20365
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0203:Particle-, nuclear-, astro-physics, and related fields
• Research Institution: The University of Tokyo (2022); Yokohama National University (2021)
• Principal Investigator: Asai Kento 東京大学, 宇宙線研究所, 特任研究員 (00913774)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 暗黒物質 / 長寿命粒子探索実験 / 標準模型を超える物理 / 素粒子現象論

Outline of Final Research Achievements

Dark matter with light masses below GeV recently has attracted much attention. Because of their lightness, light dark matters from the galactic center do not have enough energy to recoil nucleons and thus avoid strong limits by direct detection experiments. On the other hand, long-lived particle search experiments such as beam dump experiments can produce high-energy dark matters and can detect them by recoil events.
In this study, I have discussed light dark matter searches by the ILC beam dump experiment, which is a long-lived particle search experiment using the International Linear Collider (ILC), an electron-positron linear accelerator planned in Japan, and shown that the ILC beam dump experiment has a sensitivity to dark matters.

Free Research Field

素粒子現象論

Academic Significance and Societal Importance of the Research Achievements

暗黒物質は、様々な宇宙観測によって存在が確かであると考えられていながら、その性質はほとんど解明されていない。さまざまな直接・間接実験によって精力的に暗黒物質探索が行われているにもかかわらず暗黒物質は未だ発見されていない現在，これらの実験による探索が困難な軽い暗黒物質模型にも視野を向ける必要がある．
本研究は，そのような暗黒物質に対して，長寿命粒子探索実験が非常に強力な探索手段になりうることを明らかにした点で重要である．また，現在提案中のILCの新たな可能性を開いた点においても意義深いと言える．