Study of Weak Hyperon Nucleon Interaction by means of Decay Particle Spectroscopy

衰变粒子光谱研究弱超子核相互作用

• 批准号: 08239205
• 负责人: KISHIMOTO Tadafumi
• 金额: $ 35.33万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research 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-08239205/
• 关键词: Hypernuclei; Strangeness; Weak nonmesonic decay; Spin-orbit interaction; Baryon-Baryon Interaction; Short range correlation; Quark degree of freedom; ハイペロン核子相互作用; 非対称弱崩壊; 偏極; 弱崩壊; パリティ非保存

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 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 focused our attention to the phenomena which originate short range interaction. Following subjects were studied in this research.(1) 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.(2) 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ィイD1-ィエD1, πィイD1-ィエD1) using kaon beam provided 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.(3) Production of strangeness by weak interaction.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 designing 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振动。必须在模型中进行距离。范围相互作用。 λλλλλλλλλλ已知为小，尽管没有确定的值是通过实验产生的。 。发现分裂是弱相互作用的20-40倍。通过仔细设计检测器，相互作用是可行的。

项目成果

D.G.Watts: "Single and Double Delta Production in the ^3He(γ,π^+π^-)Reaction at 380【less than or equal】Eγ【less than or equal】700 MeV" Physical Review C. 55巻・4号. 1832-1842 (1997)

D.G.Watts：《^3He(γ,π^+π^-)Reaction at 380【小于或等于】Eγ【小于或等于】700 MeV 中的单和双 Delta 产生》《物理评论 C》第 55 卷、第 4 卷第 1832-1842 号 (1997)

H. Nabetani, T. Oagito, T. Sato, T. Kishimoto: "Spin observation in the pn → pΛ reaction"Phys. Rev.. C60. 017001 1-4 (1999)

H. Nabetani、T. Oagito、T. Sato、T. Kishimoto：“pn → pΛ 反应中的自旋观察”Phys. Rev. 017001 1-4 (1999)。

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. Takahashi, T. Hasegawa, H. Bhang, Y. Kim, H. Park, and M.

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.

Tadafumi Kishimoto: "Kaonic nuclei excited by the (Κ^-, Ν) reaction"Phys. Rev. Lett.. 83. 4701-4704 (1999)

Tadafumi Kishimoto：“由 (K^-, N) 反应激发的 Kaonic 核”Phys. Rev. Lett.. 83. 4701-4704 (1999)

Tadafumi Kishimoto: "Strangeness changing baryon baryon interaction"Nucl. Phys., Proc. Int. Conf on Quark Lepton Nuclear Physics(QULEN97), Osyaka, 20-23 May, 1997. A629. 369c (1998)

岸本忠文：“奇异性改变重子重子相互作用”Nucl。