Production of Light Single-LAMBDA and Double-LAMBDA Hypernuclei in XI^- Atomic Capture Reaction

XI^- 原子捕获反应中轻单 LAMBDA 和双 LAMBDA 超核的产生

• 批准号: 06640415
• 负责人: YAMADA Taiichi
• 金额: $ 1.41万
• 依托单位: Kanto Gakuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640415/
• 关键词: Hypernuclei; Hyperon; Strangeness; Nuclear theory; Atomic capture reaction; Double-LAMBDA hypernucleus; Nuclear deep-hole state; Selection rule; ハイパー核; ストレンジネス; ダブルラムダ核; 核反応; グナイ粒子

1) The production rates per XI for the LAMBDALAMBDA^<12>Be+p, LAMBDALAMBDA^<12>B+n, LAMBDALAMBDA^<11>Be+d, LAMBDALAMBDA^9Li+alpha, LAMBDALAMBDA^<10>Be+t, LAMBDALAMBDA^6He+^7Li, LAMBDALAMBDA^5He+^8Be, LAMBDA^8Li+LAMBDA^5He, LAMBDA^9Be+LAMBDA^4H and LAMBDA^<12>B+LAMBDA channels (including their excited channels) via the ^<12>C-XI^- atomic states have investigated within the fame of the doorway double-LAMBDA hypernuclear picture (direct reaction picture). We found that in the stopped XI^- reaction the excited double-LAMBDA hypernuclear states for LAMBDALAMBDA^<12>B,LAMBDALAMBDA^<12>Be and LAMBDALAMBDA^<11>Be are greatly produced via the resonant states of the final double-LAMBDA hypernuclear channels. The following sequential process is possible ; (^<12>C,XI^-) atom * LAMBDALAMBDA^<12>B^<**>+n * LAMBDALAMBDA^<11>Be+p+n or LAMBDALAMBDA^<11>B+n+n. This process is similar to the sequential process for LAMBDALAMBDA^<13>B production observed in the KEK-E176 experiment, (^<14>N,XI^-) atom ** LA … More MBDALAMBDA^<14>C^*+n * LAMBDALAMBDA^<13>B+p+n. The calculated double-LAMBDA sticking probability is about 5 %, which is in correspondence to the experimental data.2) The excitation functions of the ^9Be(K^-, K^+)XI^9He reaction at P_K=1.6 GeV/c and rheta=0ﾟwere ecaluated with the Woods-Saxon type (VO=-24 and -16 MeV) and folding-type (YNG-ND No.1 and No.2) XI^--^8Linuclear potentials. The XI^--^8Li nuclear potentials except the folding potential (YNG-ND No.1) gives a broad peak at the XI bound-state region, which cross section is 0.02 - 0.08mub (0.2nb for YNG-ND No.1). The peak consists of the three component coming from the three XI^9He bound states. We estimated the production cross section of XI^9He (g.s.) * LAMBDALAMBDA^8He + n for the XI^--^8Li nuclear potentials. The calculated production rates were about 0.4%, and then, the production cross sections were 0.03 - 0.1 nb (0.3 pb) for the XI^--^8Li nuclear potentials except the folding potential (YNG-ND No.1)3) A selection rule for fragmentations of doorway s-hole states in light nuclei was given. In the two-body fragmentation process of the doorway s-hole states in light nuclei, smaller fragments than the alpha particle (p, n, d, t, and 3He) are allowed, while the fragments such as the alpha particle and the larger particles are forbidden, in spite of the fact that the Q value for the alpha fragment is similar to or even larger than those for the p, n, and d fragments. The selection rule comes from the spatial symmetry of the dooray s-hole states, The spectroscopic factors and partial widths for the two-body fragmentations of the s-hole of ^<11>B and ^<15>N are calculated to show the selection rule. The calculated escaping widths for the ^1B (s-hole) and ^<15>N (s-hole) doorway states are ingood correspondence with the experimental widths. This may suggest that the following scenario is realized ; in the light nuclei the fragmentation process of the s-hole state in the doorway stage is superior or competitive to that in the compound nuclear stage. Less

1)在门口双LAMBDA超核图像（直接反应图像）的范围内，研究了LAMBDALAMBDA ^<12>Be+p、LAMBDALAMBDA^<12>B+n、LAMBDALAMBDA ^<11>Be+d、LAMBDALAMBDA ^9 Li + α、LAMBDALAMBDA^<10>Be+t、LAMBDALAMBDA ^6 He +^7 Li、LAMBDALAMBDA ^5 He +^8 Be、LAMBDA ^8 Li + LAMBDA ^5 He、LAMBDA ^9 Be + LAMBDA ^4 H和LAMBDA^<12>B+LAMBDA通道（包括它们的激发通道）通过^<12>C-XI^原子态的每XI产生率。我们发现，在停止的XI^-反应中，LAMBDALAMBDA^<12>B、LAMBDALAMBDA^<12>Be和LAMBDALAMBDA^<11>Be的激发双LAMBDA超核态是通过最终双LAMBDA超核通道的共振态大量产生的.以下顺序过程是可能的;（^<12>C，XI^-）atom * LAMBDALAMBDA^<12>B^**&gt;+n * LAMBDALAMBDA^<11>Be+p+n或LAMBDALAMBDA^<11>B+n+n。该过程类似于<13>KEK-E 176实验中观察到的LAMBDALAMBDA^ B产生的顺序过程，（^<14>N，XI^-）原子 ** LA ...更多信息 MBDALAMBDA^<14>C^*+n * LAMBDALAMBDA^<13>B+p+n。2）用Woods-Saxon型（VO=-24和-16 MeV）和折叠型（YNG-ND No.1和No.2）XI^--^8单核势计算了P_K=1.6 GeV/c和rheta=0 μ m时^9Be（K^-，K^+）XI ^9 He反应的激发函数。除了折叠势（YNG-ND No.1）外，XI^--^8Li核势在XI束缚态区有一个宽峰，其截面为0.02 - 0.08 μ b（YNG-ND No.1为0.2nb）。该峰由来自三个XI^9He束缚态的三个分量组成。我们估计了XI^9 He的产生截面（g.s.）* LAMBDALAMBDA^8He + n的XI^--^8Li核势。计算得到的产生率约为0.4%，除折叠势（YNG-ND No.1）外，XI^-^8Li核势的产生截面为0.03 - 0.1 nb（0.3 pb）。在轻核门口s空穴态的两体碎裂过程中，允许产生比α粒子（p、n、d、t和3 He）更小的碎片，而禁止产生α粒子和更大的粒子，尽管α碎片的Q值与p、n和d碎片的Q值相似或甚至更大。这种选择规则来自于多垒s空穴态的空间对称性。计算了^ B和^ N的s空穴两体碎裂的光谱因子和部分宽度<11><15>，说明了这种选择规则。计算得到的^1B（s-hole）和^<15>N（s-hole）门道态的逃逸宽度与实验值吻合得很好。这可能表明以下情况是实现的：在轻核中，S-空穴态在门口阶段的碎裂过程是上级或竞争的复合核阶段。少

项目成果

T.Yamada: "Double-Λ,Twin-Λ and Single-Λ Hypernuclear Production for Stopped Ξ^-Particle in ^<12>C" Preprint KGU-P9601 (Kanto Gakuin University). (1996)

T.Yamada：“^12C 中停止的 Ξ^ 粒子的双Λ、双Λ 和单Λ 超核生产”预印本 KGU-P9601（关东学院大学）（1996 年）。

T.Yamada and Y.Yamamoto: "SIGMA^- atoms and ^4_MAHe Hypernucleus with SIGMA-N Interactions" Progress of Theoretical Physics Supplement. No.117. 241-250 (1994)

T.Yamada 和 Y.Yamamoto：“SIGMA^- 原子和 ^4_MAHe 超核与 SIGMA-N 相互作用”理论物理进展补充。

T.Yamada: "Double -LAMBDA and Twin-LAMBDA Hypernuclear Production in XI^--atomic Capture into ^<12>C" Genshikaku Kenkyuu. 40. 23-25 (1995)

T.Yamada：“XI^-原子捕获到 ^<12>C 中的双 LAMBDA 和双 LAMBDA 超核生产”Genshikaku Kenkyuu。

T.Yamada and K.Ikeda: "Double-LAMBDA Hypernuclear Production via XI Hypernuclear States in the ^9Be (K^-, K^+) XI^9He reaction" Preprint KGU-P9602 (Kanto Gakuin University). (1996)

T.Yamada 和 K.Ikeda：“^9Be (K^-, K^ ) XI^9He 反应中通过 XI 超核状态产生双 LAMBDA 超核”预印本 KGU-P9602（关东学院大学）。

T.Yamada: "Twin Λ-hypernuclear production in Ξ^--atomic capture into ^<12>C" Nuclear Physics A. 585. 79c-82c (1995)

T. Yamada：“Ξ^ 中的孪生 Λ-超核产生 - 原子俘获到 ^<12>C”核物理 A. 585. 79c-82c (1995)