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arXiv 1003.1615nucl-th
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$K^-$在原子核中的静止吸收和随后的$p Λ$发射的研究

Study of $K^-$ absorption at rest in nuclei followed by $p Λ$ emission

Grishma Pandejee, N. J. Upadhyay, B. K. Jain

摘要:

本文用量子力学散射理论和原子核波函数研究了$K^-$在原子核中静止吸收后的符合$p\,Λ$发射。假设$K^-$吸收发生在原子核中的两个质子上。在形式上,重点研究了$p$和$Λ$与反冲核的末态相互作用效应。我们在FSI中包括弹性散射和单核子敲除(KO)通道。计算的$^{12}$ C核,使用壳模型波函数,没有任何额外的质量修改的$K^-\,pp$系统的核。计算了$p$和$Λ$的角关联分布、不变质量分布以及$p$和$Λ$的动量谱。这些结果与相应的实验测量\cite{agnello}进行了比较。在仅考虑弹性散射FSI的情况下,角相关分布和动量谱与相应的测量结果符合得很好。在全FSI条件下,计算得到的$p\,Λ$不变质量分布有两个峰,一个对应于弹性散射FSI,另一个对应于单核子KO FSI。KO峰的位置和形状与参比品\cite{agnello}中观察到的峰完全一致。对应于弹性散射FSI的峰似乎不存在于测量的分布中。考虑到这种双峰结构总是在中能核的包容性($p$,$p^\prime $)和($e$,$e^\prime $)反应中观察到,在$p\,Λ$反应中没有弹性散射峰是令人感兴趣的。

英文摘要:

$p\,Λ$ emission in coincidence following $K^-$ absorption at rest in nuclei is studied using quantum mechanical scattering theory and nuclear wave functions. $K^-$ absorption is assumed to occur on two protons in the nucleus. In the formalism, emphasis is put on the study of the final state interaction (FSI) effects of $p$ and $Λ$ with the recoiling nucleus. We include elastic scattering and single nucleon knock-out (KO) channels in the FSI. Calculations are presented for the $^{12}$C nucleus, using shell model wave functions, and without any extra mass modification of the $K^-\,pp$ system in the nucleus. Calculated results are presented for the angular correlation distribution between $p$ and $Λ$, their invariant mass distribution and the momentum spectra of $p$ and $Λ$. These results are compared with the corresponding experimental measurements \cite{agnello}. With only elastic scattering FSI included, the angular correlation distribution and the momentum spectra are found to be in good accord with the corresponding measurements. With full FSI the calculated $p\,Λ$ invariant mass distribution is found to have two peaks, one corresponding to the elastic scattering FSI and another to single nucleon KO FSI. The KO peak agrees fully, in position and shape, with the peak observed in Ref. \cite{agnello}. The peak corresponding to elastic scattering FSI does not seem to exist in the measured distribution. Considering that such a two peak structure is always seen in the inclusive ($p$, $p^\prime $) and ($e$, $e^\prime $) reactions in nuclei at intermediate energies, absence of the elastic scattering peak in the $p\,Λ$ reaction is intriguing.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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