A new challenge of the KamLAND-Zen experiment aiming at discovery of the Majorana nature of neutrinos.
Project/Area Number |
17H01120
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Research Category |
Grant-in-Aid for Scientific Research (A)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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Research Institution | Tohoku University |
Principal Investigator |
Shirai Junpei 東北大学, ニュートリノ科学研究センター, 学術研究員 (90171032)
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Project Period (FY) |
2017-04-01 – 2021-03-31
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Project Status |
Completed (Fiscal Year 2020)
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Budget Amount *help |
¥31,720,000 (Direct Cost: ¥24,400,000、Indirect Cost: ¥7,320,000)
Fiscal Year 2020: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Fiscal Year 2019: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Fiscal Year 2018: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2017: ¥23,270,000 (Direct Cost: ¥17,900,000、Indirect Cost: ¥5,370,000)
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Keywords | ニュートリノ / 2重ベータ崩壊 / カムランド禅 / 液体シンチレータ / キセノン |
Outline of Final Research Achievements |
The purpose of KamLAND-Zen experiment is to search for undiscovered neutrinoless double beta decay (0νββ decay) using 136Xe nuclei, which is the unique test of Majorana nature of neutrinos : neutrinos and antineutrinos are identical particles. In this study construction of a new mini-balloon for the KamLAND-Zen which holds liquid scintillator dissolved with 750 kg xenon gas enriched with 136Xe nuclei was made, and the 0νββ decay search by taking high-quality data was started for the experiment. The new balloon was confirmed to be clean enough and the data taking has been stably continued. In addition, new analysis methods have been introduced to remove background events and various efforts have been made to improve the detector performance, which significantly made better the sensitivity.
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Academic Significance and Societal Importance of the Research Achievements |
ニュートリノは電荷がなくそれ自体が反粒子の可能性(マヨラナ性)があり、事実ならニュートリノの質量が他の素粒子に比べ何桁も小さいことや、現在の宇宙が物質ばかりであることの謎が説明できる可能性がある。実験的には原子核の0νββ崩壊を見つけることが鍵のため世界的に実験が進行中である。カムランド禅はキセノンを使った世界最高感度の実験で、本研究はその中核であるバルーンを新たに導入し、高品位のデータ採取による感度の向上に成功した。0νββ崩壊が見つかれば世紀の大発見であり、我々を含め現在の宇宙がなぜ存在するのかの深淵な問いに科学の道筋をつけることができる。本研究はこれに迫る研究である。
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Report
(5 results)
Research Products
(22 results)
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[Journal Article] Double Beta Decay2018
Author(s)
Junpei Shirai
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Journal Title
International Journal of Modern Physics: Conference Series
Volume: 46
Pages: 1860002-1860002
DOI
Related Report
Open Access
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[Journal Article] KamLAND2017
Author(s)
Junpei Shirai
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Journal Title
Proceedings of Science(NEUTEL2017)003
Volume: 307
DOI
Related Report
Open Access
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