Study of Nuclei with S = -2

S = -2 的原子核研究

• 批准号: 08239101
• 负责人: FUKUDA Tomokazu
• 金额: $ 98.18万
• 依托单位: High Energy Accelerator Research Organization (1997-1998)The University of Tokyo (1996)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-08239101/
• 关键词: Hypernuclei; Strangeness; Double-lambda nuclei; H particle; Weak decay; Hyperon-nucleon interaction; Cylindrical Detector; Hybrid emulsion; グザイ核; 中間子弱崩壊; エマルジョン、カウンター複合実験; K中間子; 大立体角円筒型スペクトロメーター; ハイブリッド・エマルション; ファイバーシンチレータ

The study of nuclear systems with strangeness (S) = -2 is quite important in order to understand the baryon-baryon interactions in an unified way and it will also give us a basis toward a new form of the nuclear matter such as strange quark matter. However the experimental study of S = -2 nuclear systems has been limited so far ; only two reports of the double-lambda(DL) hypernuclei since 1960's. We carried out two complementary experiments in order to create and identify DL hypernuclei by more than one order of magnitude than before ; one is E906 at BNL-AGS, where relatively light DL hypernuclei will be identified by observing two successive decaying pions with Cylindrical Detector Systems (CDS) and the other is to use a novel technique, i,e. a hybrid emulsion technique (KEK-PS E373). The analysis of E906 is at the final stage and we obtain interesting results ; we have succeeded to create more than a few tens of the lightest DL hypernuclei, ィイD14ィエD1HィイD2ΛΛィエD2. This is the first experiment with such high statistics and will open a new way towards the study of S = -2 nuclear systems with future high-intensity accelerators. We have also obtained the cross sections of Ξp elastic and Ξp -> ΛΛ. The analysis of E373 is under way and we will accumulate more data in the next April. We hope to eventually identify various species of DL hypernuclei with better statistics by one order of magnitude than before.

奇异度（S）= -2的核系统的研究对于统一理解重子-重子相互作用是十分重要的，同时也为我们研究新形式的核物质（如奇异夸克物质）提供了基础。然而，对S = -2核系统的实验研究还很有限，自20世纪60年代以来，只有两个关于双λ超核的报道。我们进行了两个互补的实验，以创建和识别DL超核比以前多一个数量级;一个是在BNL-AGS的E906，其中相对较轻的DL超核将通过观察两个连续的衰变π介子与圆柱探测器系统（CDS）和其他使用一种新的技术，即，混合乳液技术（KEK-PS E373）。对E906的分析已进入最后阶段，我们获得了有趣的结果;我们已经成功地创造了几十个最轻的DL超核，即D14超核D1 H超核D2ΛΛ超核D2。这是第一个具有如此高统计数据的实验，将为未来高强度加速器研究S = -2核系统开辟一条新的途径。我们还得到了双曲p弹性截面和双曲p -> ΛΛ截面。E373的分析正在进行中，我们将在明年4月积累更多数据。我们希望最终确定不同种类的DL超核与更好的统计比以前的一个数量级。

项目成果

T. Fukuda: "Production of Double-Λ Hypernuclei : BNL-AGS E906"Proc. of APCTP Workshop on Strangeness Nuclear Physics, Seoul, Feb. 19-22. (in press). (1999)

T. Fukuda：“双Λ超核的产生：BNL-AGS E906”，APCTP 奇异核物理研讨会，首尔，2 月 19-22 日（出版中）。

Tomokazu Fukuda: "Search for ΛΛ Hypernuclei by Sequential Pionic Decays (E906)"Nuclear Physics. A639. 355c-362c (1998)

Tomokazu Fukuda：“通过连续π衰变搜索 ΛΛ 超核 (E906)”核物理。355c-362c (1998)

T. Fukuda: "Production of Double -Λ Hypernuclei : BLN-AGS E906"Nuclear Physics. (印刷中).

T. Fukuda：“双-Λ超核的产生：BLN-AGS E906”核物理（正在出版）。

J. Nakano: "Study of Double Strangeness System (S=-2) with Cylindrical Detector System (CDS)"Proc. of Asia Pacific Conference on Few-Body Problems in Physics, Noda/Kashiwa(Japan), Aug. 23-28. (in press). (1999)

J. Nakano：“带有圆柱形探测器系统（CDS）的双奇异系统（S=-2）的研究”Proc。

S. Aoki: "Quasifree p(Κ^-,Κ^+)Ξ^- Reaction in Nuclear Emulsion"Nuclear Physics. A644. 365-385 (1998)

S. Aoki：“核乳液中的准自由 p(Κ^-,Κ^+)Ξ^- 反应”核物理 365-385。