2022 Fiscal Year Final Research Report
Search for solar KK axion using low-pressure gas detectors
| Project/Area Number |
21K13932
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| Research Category |
Grant-in-Aid for Early-Career Scientists
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| Allocation Type | Multi-year Fund |
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| Review Section |
Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
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| Research Institution | The University of Tokyo |
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Principal Investigator |
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| Project Period (FY) |
2021-04-01 – 2023-03-31
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| Keywords | ガス検出器 / アクシオン / 余剰次元 |
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| Outline of Final Research Achievements |
A proof-of-principle experiment of KK axion search by gas detector was performed using a micro-pixel chamber detector (10x10x1 cm3) filled with Ar:C2H6 (9:1) gas mixture. 5.9 keV emitted by Fe-55 produces 3 keV of Ar characteristic X-rays. The remaining 3 keV can be detected simultaneously. By detecting these (3keV+3keV) simultaneously, we confirmed that this study can sufficiently observe the KK axion decay signal (5keV+5keV). In addition, a detector (10x10x10 cm3) was fabricated for observation and installed in the underground laboratory. After confirming that the signal from the source can be detected, the detector is under commissioning for stable observation.
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| Free Research Field |
宇宙素粒子
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| Academic Significance and Societal Importance of the Research Achievements |
余剰次元を伝播するアクシオン"Kaluza-Klein（KK）アクシオン"は素粒子物理学の謎を複数解決可能な，未発見の素粒子である。太陽内部で生成され重力的に太陽系内に捉えられた”太陽KKアクシオン”は10keV程度の質量と有限な寿命（10^11 ~ 10^17日）を持ち，その崩壊によって放出される二光子（5keV+5keV）を捉えることで地球でも観測の可能性がある。本研究で用いるガス検出器では二光子を分離して捉えられるため強力な背景事象除去能力が得られる。また，検出器内崩壊頻度は有効体積のみに依存する。ガス検出器はの大型化は比較的容易で，有効体積拡張性の高さも本研究の強みである。
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