The first measurement of the scattering length and the effective range of Lambda-n intearaction
| Project/Area Number |
18H01220
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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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 | Tohoku University |
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Principal Investigator |
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| Project Period (FY) |
2018-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2022)
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| Budget Amount *help |
¥17,680,000 (Direct Cost: ¥13,600,000、Indirect Cost: ¥4,080,000)
Fiscal Year 2021: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2020: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2019: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2018: ¥10,400,000 (Direct Cost: ¥8,000,000、Indirect Cost: ¥2,400,000)
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| Keywords | ストレンジネス核物理 / バリオン間相互作用 / 光生成反応 / 検出器開発 / ストレンジネス |
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| Outline of Final Research Achievements |
In order to clarify the interaction between Λ particles and nucleons, which is not well understood, we aim to determine the scattering length and effective range of Λ and neutron (n) with high accuracy, which have not been measured so far. In order to carry out the experiment, we have upgraded the NKS2 spectrometer, which has been used for the experiments on strangeness photoproduction reactions with real photon beams at the Research Center for Electron Photon Science, Tohoku University. We have collected data and are analyzing the data. In addition, we have performed a Λnn bound state search experiment with a tritium target at the Jefferson Laboratory in the USA. We obtained an upper limit on the production cross section and that provides a theoretical limit on the Λnn interaction.
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| Academic Significance and Societal Importance of the Research Achievements |
ハイペロンはSクォークを含む核子（陽子や中性子）の仲間である。ハイペロンの一つであるΛと核子との間に働く力は、ハイパー核中でのΛの束縛エネルギー測定を中心として進められてきた。これまで多くの実験データを再現してきた理論モデルでは、最近の軽いハイパー核について陽子と中性子の間の対象性：荷電対象性、を説明出来ないことが確定されている。この謎を解明するため、これまで行われていないΛと中性子の相互作用を測定する実験を遂行した。実験結果から理論モデルに制約を与えることができた。今後より高統計の実験を行うことで、ストレンジネスを含むバリオン間相互作用のより本質的理解につながるであろう。
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Report
(5 results)
Research Products
(16 results)
