K介子部分子分布函数的研究

发布时间：2017-12-27 22:32

本文关键词：K介子部分子分布函数的研究　出处：《华东师范大学》2016年硕士论文　论文类型：学位论文

【摘要】：上世纪三十年代,日本物理学家汤川秀树(Hideki Yukawa)提出π介子理论来解释核子之间的相互作用,随着后来许多新粒子的不断发现,人们对介子的研究逐步展开。目前物理学家们对π介子中的价夸克分布函数的研究已经比较成熟,组分夸克模型、非定域手征夸克(NLChQM)模型、NJL(Nambu-Jona-Lasinio)模型等已经给出了各自的研究结果,但对K介子的研究结果还有较大分歧。根据量子色动力学理论,DGLAP(Dokshitzer-Gribov-Lipatov-Alarelli-Parisi)演化方程是描写部分子演化的基本方程,一个大动量的部分子可以演化成两个较小动量的部分子。按照这个动力学演化机制,大动量的部分子不断地辐射小动量的部分子,所以在x越小的区域,部分子的数目就越多,最终散射截面的幺正性将被破坏。而ZRS(Zhu-Ruan-Shen)演化方程比较完整地考虑了演化过程中的遮蔽效应和反遮蔽效应,在本文用该方程对K介子的部分子分布函数进行研究。本文对K介子的研究主要包括以下几个方面：1、对当前研究K介子的主要模型：组分夸克模型和非定域手征夸克模型进行比较,分析了各模型中价夸克分布函数形式的异同。2、对标准的演化方程DGLAP演化方程进行介绍,分析其局限性进而提出将ZRS演化方程运用到对介子中部分子分布函数的研究中去。3、本文选取的演化起点Q2=0.074GeV2,选取合适的初始分布只包含价夸克没有海夸克和胶子,通过与NA3小组的实验结果进行比较分析,得出了相应的初始分布。4、最后,分析了K介子中各部分子所占的动量比例、动量分布,并与其它模型进行了比较,我们的结果应该是处在一个合理的范围内。
[Abstract]:In the 30s of last century, Japanese physicist Yukawa Hideki (Hideki Yukawa) put forward the theory of PI meson to explain the interaction between nucleons. With the discovery of many new particles, people began to study mesons. Now physicists to study the valence quark distribution function of the pion is relatively mature, the constituent quark model and nonlocal chiral quark model (NLChQM), NJL (Nambu-Jona-Lasinio) model have been given their own research results, but the results of the K meson and larger differences. According to the theory of quantum chromatic dynamics, the DGLAP (Dokshitzer-Gribov-Lipatov-Alarelli-Parisi) evolution equation is the basic equation describing partial sub evolution. A large momentum part can evolve into two smaller momentum parts. According to this dynamic evolution mechanism, the parts of large momentum continue to radiate the parts of small momentum, so in the smaller X region, the number of Parton is more, and the uniformity of the final scattering section will be destroyed. The ZRS (Zhu-Ruan-Shen) evolution equation takes into account the shadowing effect and the anti shadowing effect in evolutionary process. In this paper, the partial distribution function of K meson is studied by using the equation. The research of K meson mainly includes the following aspects: 1. Compare the main models of K meson: component quark model and nonlocality chiral quark model, and analyze the similarities and differences of the valence quark distribution function in each model. 2, introduce the standard evolution equation DGLAP evolution equation, analyze its limitations, and put forward the application of ZRS evolution equation to the study of molecular distribution function in the middle part of meson. 3, the evolution point Q2=0.074GeV2 selected in this paper selects the suitable initial distribution, which contains only the quark, no sea quark and gluon. By comparing with the experimental results of NA3 group, we get the corresponding initial distribution. 4, at last, we analyze the momentum proportion and momentum distribution of each part in K meson, and compare it with other models. Our results should be in a reasonable range.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O572.33

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