Molecular Structures of Strangeness Light-nuclei and their Response Spectra

奇异轻核的分子结构及其响应谱

基本信息

批准号：
13640302
负责人：
HARADA Toru
金额：
$ 2.11万
依托单位：
Osaka Electro-Communication University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

1.Mean-field calculations for strangeness-nucleiHartree-Fock (HF) and Density-dependent Hartree-Fock (DDHF) calculations for hypernuclei are performed on the basis of ΝΝ and ΛΝ effective interactions with a finite-range. We discuss structures of ^<17>_ΛO and ^5_ΛHe and core-polarization effects arising from the addition of the Λ-hyperon. We stress that the core-polarization (rearrangement) energy ΔE_N is 〜2 MeV for (Os)_Λ and 〜1 MeV for (Op)_Λ in the DDHF. The reason why the total energy E_N of the core is reduced is because the nucleon s.p. energy e_α becomes deeper by the addition of the Λ. Energies of ΔE_N depend on the nature of the ΝΝ effective interaction and the capacity of the ΛΝ effective interaction to reproduce the experimental data.2.Production of strangeness-nuclei and their response spectraWe propose an "optimal Fermi-averaging approximation" to nuclear reactions within the DWIA. We apply it to calculate A quasi-free spectra from ^<12>C(π^+,K^+) reactions, and compare them with experimental data. The results show that the calculated spectra are in excellent agreements with the data, because the energy-dependence originates from the nature of the optimal Fermi-averaging t-matrix. Then we extend it (π^-,K^+) spectra on ^<12>C and ^<28>Si targets in order to extract properties of Σ^--nucleus potential from the data. We find that the Σ^--nucleus potential for ^<28>Si has a repulsion of V^0_Σ【similar or equal】 +20 〜 +40 MeV, and a sizable absorption of -10 〜 -30 MeV for a Woods-Saxon type potential, and that a Σ^--nucleus potential reproducing the Σ^-atomic x-ray data, would reproduce the (π^-,K^+) spectra. Moreover, we predict that the ^4_ΛHe ground state is populated by about 20% via Σ components in (stopped K^-,π^-) reactions, using a coupled (3Ν-Λ)+(3Ν-Σ) models.

1. nucleihartree-fock（HF）和密度依赖性的Hartree-fock（DDHF）计算高核中的含量场计算，是根据ννν和λν与有限范围的有效相互作用进行的。我们讨论 ^<17>_λO和 ^5_λHE的结构以及添加λ-hyperon产生的核心化效应。我们强调的是，DDHF中的核心化（重排）能量ΔE_n为（OS）_λ和（OP）_λ的〜2 meV。核心的总能量E_N减少的原因是核S.P.通过添加λ，能量E_α变得更深。 ΔE_N的能量取决于νν有效相互作用的性质以及λν有效相互作用重现实验数据的能力。2。陌生核酸菌的生产及其反应谱谱提出了“最佳的fermi-narterake近似近似”对德维亚内部的核反应。我们将其应用于从^<12> c（π^+，k^+）反应中计算出无准光谱，并将它们与实验数据进行比较。结果表明，计算出的光谱与数据达成了极好的协议，因为能量依赖性起源于最佳fermi-vermi-vermi-vermi-vermi-vermi-terraging t-matrix的性质。然后，我们将其扩展（π^ - ，k^+）光谱在^<12> c和^<28> si目标上，以从数据中提取σ^ - 核电位的性能。我们发现，^<28> si的σ^ - 核潜力的排斥力为V^0_σ【相似或相等的+20〜 +40 MEV，木材saxon型潜力的-10〜-30 MEV遭受了可观的-10〜-30 MeV，并且acleus潜在地重现了σ^^-ATAMIC x-ar x-ray +seppects +seppect^ +seppects^kempect^ +）此外，我们预测，使用耦合（3ν-λ）+（3ν-σ）模型中的（停止k^ - ，π^ - ）反应（停止k^ - ，π^ - ）反应中的σ分量约为20％。