QUARK AND GLUON FRAGMENTATION FUNCTIONS IN MODEL CALCULATIONS

夸克與膠子破碎函數的模型計算

楊東憬(Yang Dong-Jing)

指導教授 ： 江府峻

國立臺灣師範大學/理學院/物理學系/博士(2019年)

https://doi.org/10.6345/NTNU201900509

摘要

none

關鍵字

Quark fragmentation functions ； Gluon fragmentation functions ； Jet ； Hadronization ； NJL model ； Nonlocal chiral quark model

並列摘要

In this thesis we will introduce the flow of model calculations for parton fragmentation functions. The parton fragmentation functions have many types. Such as transverse-momentum dependent or integrated ones. People can start from the definition of operator and Fierz identity. Because the degree of freedom and there are many produced hadrons in the final state, the jet algorithm is a good choice to describe such process. In the jet algorithm, the whole hadronization is divided into steps. The processes associated with one step emission are called elementary fragmentation functions and can be calculated with effective models. The currently used models are the Nambu–Jona-Lasinio (NJL) model and the nonlocal chiral quark model (NLChQM). Both two models can explain a lot of low energy physics. With elementary fragmentation functions, we can obtain fragmentation functions of entire hadronization processes by computing the corresponding integral equations. Three methods are provided to handle with integral equations. We present our results of model calculations. Some overcomes from other papers are not correct. We points these out and show the correct results. To compare with the cross section of $e^+e^-$ annihilation, we also evolve the results to a higher energy scale using QCD evolution.

並列關鍵字

Quark fragmentation functions ； Gluon fragmentation functions ； Jet ； Hadronization ； NJL model ； Nonlocal chiral quark model

參考文獻

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