Spectra of Strangeness Production Reactions and Baryon Excited States in Nuclear Medium

核介质中奇异产生反应和重子激发态的光谱

基本信息

批准号：
15540284
负责人：
KOHNO Michio
金额：
$ 0.7万
依托单位：
Kyushu Dental College
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

The study of the Σ-N interaction is essential to understanding the physics of octet baryons. However, in contrast to the A, the Σ single-particle (s.p) potential in nuclear media, which reflects basic properties of the Σ-N interaction, has not been established, because experimental information is scare. Even its sign has not been established Recently, (π^-,K^+) spectra corresponding to Σ formation were measured employing various nuclei targets at KEK with better precision, using 1.2 GeV/c π^-. Based on these spectra, it was found that the potential deduced from their DWIA analysis is strongly repulsive, as large as 100 MeV. Considering the importance of understanding the Σ-N interaction for our description of the whole octet baryon-baryon interactions, it is desirable to carry out an independent analysis of the KEK experiments. In this study, I develop a semiclassical method for the DWIA approach and apply it to (π^-,K^+) inclusive spectra. The expression of the double differential cross section consists of the incoming pion distorted wave function, the outgoing kaon distorted wave function and the undetected hyperon distorted wave function at each collision point, where conservation of the classical local momentum holds. The application of this model to the (π^-,K^+) inclusive spectrum obtained with 28Si targets at KEK has shown that the shape and magnitude of the spectrum is satisfactorily reproduced by a repulsive Σ-nucleus potential of the order of 30-50 MeV. This magnitude, in turn, constrains the Σ-N potential model and thereby improve our understanding of the interactions between complete octet baryons. The present framework can be easily applied to describe other inclusive spectra, such as (K,π),(π,η), (γ,K), and soon. It is also straightforward to consider multistep contributions.

σ-N相互作用的研究对于理解八位位baryon的物理学至关重要。然而，与a核介质中的σ单颗粒（S.P）电位相比，反映了σ-N相互作用的基本特性，尚未建立，因为实验信息是恐慌。即使是最近尚未确定其符号，（π^ - ，k^+）光谱与σ形成相对应的光谱被使用1.2 GEV/cπ^ - 使用KEK的各种核靶标测量。基于这些光谱，发现从DWIA分析中推导的潜力是强烈的排斥力，高达100 MEV。考虑到了解我们对整个八位位baryon巴里昂相互作用的描述的σ-N相互作用的重要性，希望对KEK实验进行独立的分析。在这项研究中，我为DWIA方法开发了一种半经典方法，并将其应用于（π^ - ，k^+）包含光谱。双差分横截面的表达由传入的锥子扭曲波函数，传出的kaon扭曲波函数和在每个碰撞点处未检测到的超子扭曲波函数，其中经典局部动量的保守性保持。该模型在KEK 28SI目标获得的（π^ - ，K^+）的包含光谱中的应用表明，光谱的形状和幅度由30-50 MEV的排斥σ-核电位重现。反过来，这种大小会限制σ-N电势模型，从而提高我们对完整八位位baryons之间相互作用的理解。当前的框架可以轻松地用于描述其他包含光谱，例如（k，π），（π，η），（γ，k），很快。考虑多步骤贡献也很简单。