量子色動力學(QCD)是用來描述自然界四大基本作用力之一的強相互作用的基本規(guī)范場理論。眾所周知,強相互作用的基本粒子是夸克和膠子,并且具有兩個顯著特征:漸近自由和色禁閉。由于色禁閉,在正常條件下,實驗上尚未觀測到自由夸克,這意味著夸克總是被束縛在色單態(tài)的強子內(nèi)。格點QCD計算預言在高溫高能量密度的極端條件下會發(fā)生從強子氣到夸克解禁閉的新物質(zhì)形態(tài)夸克膠子等離子體(QGP)的相變。在實驗上通過高能重離子碰撞形成高溫高密的極端條件來尋找QGP并研究它的性質(zhì)。位于美國布魯克海文國家實驗室(BNL)的相對論重離子對撞機(RHIC)通過核核碰撞來研究QGP的性質(zhì)以及QCD相圖。RHIC自2000年運行以來,在重離子碰撞中發(fā)現(xiàn)了大量QGP存在的實驗證據(jù),例如“噴注淬火”現(xiàn)象、橢圓流的組分夸克標度性等等。這些實驗結(jié)果表明在RHIC已經(jīng)形成了強耦合的夸克膠子等離子體(sQGP),下一步的核心問題是研究QGP的特性以及QCD物質(zhì)的相結(jié)構(gòu)。由于重味夸克(粲夸克和底夸克)的質(zhì)量比較大,粲夸克約為1.3 GeV/c2和底夸克約為4.2 GeV/c2,遠遠大于∧QCD(QCD標度參數(shù))和TQGP,所以它們被認為主...

【文章頁數(shù)】：128 頁

【學位級別】：博士

【文章目錄】：
摘要
ABSTRACT
Chapter 1 Introductions
    1.1 Standard Model and Quantum Chromodynamics
        1.1.1 Standard Model
        1.1.2 Quantum Chromodynamics
    1.2 Relativistic Heavy Ion collisions
        1.2.1 Transverse momentum spectrum, Energy loss and Jet quenching
        1.2.2 Anisotropic flow
    1.3 Open heavy flavor production in HIC
        1.3.1 Heavy quarks as probes of sQGP
        1.3.2 Experimental results
Chapter 2 Experimental Setup
    2.1 The Relativistic Heavy Ion Collider
    2.2 The Solenoidal Tracker at RHIC
        2.2.1 The Time Projection Chamber
        2.2.2 The Time Of Flight detector
        2.2.3 The Barrel Electromagnetic Calorimeter
Chapter 3 Non-photonic Electron Analysis
    3.1 Run 2012 200 GeV p+p Collision Analysis
        3.1.1 Analysis principle
        3.1.2 Dataset and Event selection
        3.1.3 Track selection and Electron identification
        3.1.4 NPE raw yield extraction
        3.1.5 Efficiency and Acceptance
        3.1.6 Background subtraction
        3.1.7 Trigger/Vertex bias correction
        3.1.8 Bin shift correction
        3.1.9 Systematic uncertainties
    3.2 Run 2014 200 GeV Au+Au Collision Analysis
        3.2.1 Dataset and Event selection
        3.2.2 Centrality definition
        3.2.3 Track selection and Electron identification
        3.2.4 NPE raw yield extraction
        3.2.5 Efficiency and Acceptance
        3.2.6 Equivalent number of MB events
        3.2.7 Combine NPE results
        3.2.8 Background from J/Ψ decay
        3.2.9 Systematic uncertainties
Chapter 4 Results and Discussion
    4.1 Cross-section of NPE at low pT in 200 GeV p+p collisions
    4.2 Invariant yields and R_AA of NPE at high pT, in 200 GeV Au+Au colli-sions
    4.3 R_AA at intermediate pT in 200 GeV Au+Au collisions
    4.4 Summary
Chapter 5 Outlook
    5.1 The Heavy Flavor Tracker
    5.2 Invariant yields and R_AA of NPE in 200 GeV Au+Au collisions
    5.3 Bottom decayed electrons in 200 GeV Au+Au collisions
Bibliography
Acknowledgements
Publications



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