強(qiáng)相互作用是我們宇宙中四種基本相互作用之一,用來描述強(qiáng)子之間以及其內(nèi)部組分夸克和膠子之間的相互作用。其基本理論是量子色動力學(xué)(QCD)-SU(3)非阿貝爾規(guī)范場理論,具有漸近自由的特性。因而人們可以在高能標(biāo)區(qū)域用費(fèi)曼圖微擾展開方法處理散射問題。而在低能標(biāo)區(qū)域,強(qiáng)耦合常數(shù)變大以致微擾理論失效,QCD真空具有非平庸的結(jié)構(gòu),產(chǎn)生了動力學(xué)手征對稱性破缺和色禁閉的現(xiàn)象。為了研究這些問題,人們發(fā)展了很多非微擾方法,包括格點(diǎn) QCD,Dyson-Schwinger 方程(DSEs),Nambu-Jona-Lasinio 模型(NJL)和其他有效場論模型。在實(shí)驗方面,相對論重離子碰撞產(chǎn)生高溫高密的強(qiáng)相互作用物質(zhì),一種新的物質(zhì)形態(tài)-強(qiáng)耦合的夸克膠子等離子體被認(rèn)為會短暫形成,它可以由相對論流體力學(xué)很好地描述.在這一 QCD介質(zhì)中,夸克和膠子會從強(qiáng)子中解禁閉,擁有更長的自由程;同時手征對稱性會部分恢復(fù)。隨著介質(zhì)的膨脹,溫度和密度會降低,介質(zhì)重新強(qiáng)子化,最后末態(tài)粒子會被各種探測器收集。很顯然這是一個非常復(fù)雜的動力學(xué)過程,如何從末態(tài)粒子譜理解整個QCD物質(zhì)演化過程是非常棘手的。物理學(xué)家提出了很多實(shí)驗探針,這其中包...

【文章頁數(shù)】：111 頁

【學(xué)位級別】：博士

【文章目錄】：
摘要
Abstract
1 Introduction
2 Heavy quark radiative energy loss in Nuclei
    2.1 Background
    2.2 General framework
    2.3 Medium induced gluon radiation at twist 4
        2.3.1 Heavy-quark-gluon double scattering
        2.3.2 Interference from single and triple scatterings
    2.4 Modified fragmentation function
    2.5 Heavy quark energy loss
    2.6 Summary
3 Chiral phase transition and its critical behavior
    3.1 Background
    3.2 The Nambu-Jona-Lasinio Model
        3.2.1 The two-flavor model
        3.2.2 The three-flavor model
    3.3 Thermodynamics of NJL model
        3.3.1 The two-flavor model
        3.3.2 The three-flavor model
    3.4 Chiral restoration and the phase diagram
    3.5 Susceptibilities and the critical band in crossover region
        3.5.1 Two flavor case
        3.5.2 Three flavor case
    3.6 Critical exponents for various susceptibilities
    3.7 Summary
4 Identifying QCD phase transition with deep learning technique
    4.1 Background
    4.2 Simulation model
    4.3 Neural network and data preprocessing
    4.4 Training and testing
        4.4.1 Pure (2+1)-D hydrodynamics datasets,late transition to cascade
        4.4.2 (2+1)-D hydrodynamics+afterburner datasets,late transitionto cascade
        4.4.3 (2+1)-D hydrodynamics+afterburner datasets,early transitionto cascade
        4.4.4 Discussion
    4.5 Summary
5 Conclusions
Acknowledgements
A Susceptibilities and critical exponents
    A.1 Susceptibilities in SU(2) model
        A.1.1 Susceptibilities in free quark case
        A.1.2 Susceptibilities in interaction case
    A.2 Susceptibilities in SU(3) model
    A.3 Critical exponents for various susceptibilities
Bibliography
Resume and Publications



本文編號：4041572