Study of Short Range Hyperon Necleon Interaction

短程超子核相互作用研究

• 批准号: 10044086
• 负责人: KISHIMOTO Tadafumi
• 金额: $ 3.46万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10044086/
• 关键词: Hypernuclei; Strangeness; Weak nonmeonic decay; Spin-orbit interaction; Baryon-Baryon Interaction; Short Range correlation; Quark degeree of freedom; バリオン間相互作用; ハイペロン

It is well known that hadrons (Baryons and mesons) are made up of quarks and gluons by the strong interaction. The interaction among hadrons is not well understood especially due to our inability to describe the quark confinement beased on a known principle. The nucleon interaction is well described by meson exchange theory except at short distances where size of hadrons has to be taken into account in the model. Quark and gluon degrees of freedom have to be present though flexibility of the meson change model forbits to pin down clearly the existence of the freedom. The SU (3) extention of the model should be the best testing gound for many models that describe well the NN interaction. In the present research we forcused our attention to the phenomena which originate short range interaction. Following subjects were studied in this research.(1) Spin-orbit interaction ofィイD313(/)ΛィエD3C was measured.Spin-orbit splitting of Λ hypernuclei is known to be small though no definite value has been given by experiments. We produced ィイD313(/)ΛィエD3C by the (K-, π-) using kaon beam provied by the AGS at BNL and measured the splitting by detecting γ rays. The splitting was found to be 20-40 times smaller than that of nucleons.(2) Parity violation in the weak nonmesonic decay of hypernuclei.Weak nonmesonic decay NΛ→NN has a large momentum transfer that make interaction at short distance vital. We demonstrated production of polarized Λ hypernuclei and weak nonmesonic decay has asymmetric angular distribution corresponding parity violation. The magnitude of the parity violation is found to be inconsistent with meson exchange model. As for the further study we are preparing an experiment to measure the inverse reaction (pn→pΛ) of the weak nonmesonic decay. It is a process to produce strangeness by weak interaction. It has never been challenged. We found that the experiment is feasible by carefully desining the detector.

众所周知，Hadron（Baryons and Mesons）是由强烈的相互作用组成的夸克和灵难。在模型中，必须考虑Hadrons Hadron的大小我们的注意力是在这项研究中研究了以下受试者的theomena。 AGS ANL测量了分裂的γ射线。 λ高核和弱衰变具有不对称的角度分布，以测量弱非物质衰变的反应（Pn→Pλ）。通过仔细探测检测器可行。

项目成果

S. Ajimura, M. ishikawa, K. Ikeda, T. Kishimoto, A. Okusu, N. Shinkai, Y. Tanaka, H. Ejiri and T. Nakano, T. Nagae, K. Manabe, H. Noumi, M. Sekimoto, and T. Shibata, O. Hashimoto, K. Maeda, and T. Tak: "Asymmetry in Nonmesonic Weak Decay of Polarized 5ィイD

S. Ajimura、M. ishikawa、K. Ikeda、T. Kishimoto、A. Okusu、N. Shinkai、Y. Tanaka、H. Ejiri 和 T. Nakano、T. Nagae、K. Manabe、H. Noumi、M. Sekimoto、T. Shibata、O. Hashimoto、K. Maeda 和 T. Tak：“极化非介声弱衰变中的不对称性”

I.G.Bearden: "High Energy Pb+Pb Collisions Viewed by Pion Interferometry" Physical Review C. 58. 1656-1665 (1998)

I.G.Bearden：“通过 Pion 干涉测量观察到的高能 Pb Pb 碰撞”物理评论 C. 58. 1656-1665 (1998)

S. Ajimura, M. Ishikawa: "Polarization of ^5_ΛHe Produced by the (π^+, K^+) Reaction"Phys. Rev. Lett.. 80. 3471-3474 (1998)

S. Ajimura、M. Ishikawa：“(π^+, K^+) 反应产生的 ^5_ΛHe 的极化”Phys. Rev. Lett.. 80. 3471-3474 (1998)

T.Kishimoto: "Strange Changing Baryon Baryon Interaction" Nuclear Physics A. 629. 369-378 (1998)

T.Kishimoto：“奇怪的变化重子重子相互作用”核物理 A. 629. 369-378 (1998)

S. Ajimura, M. Ishikawa, K. Ikeda, T. Kishimoto 他: "Asymmetry in Nonmesonic Weak Decay of Polarized ^5_ΛHe Hypernucleus"Phys. Rev. Lett..

S. Ajimura、M. Ishikawa、K. Ikeda、T. Kishimoto 等人：“极化 ^5_ΛHe 超核的非介子弱衰变中的不对称性”Phys Rev. Lett..