LHC/ALICE实验质心系能量13TeV质子—质子碰撞中伴随粒子事件产生性质的研究

发布时间：2020-12-04 10:58

　　在近几十年来,夸克胶子等离子体（QGP）—直吸引着物理学家们的浓厚兴趣。夸克胶子等离子体是有别于日常强子物质的一种新的物质相态,它曾在宇宙大爆炸（Big Bang）后很短的一段时间内出现过,并深深地影响了宇宙的演化过程及现有宇宙中所有物质的形成。在夸克胶子等离子体内,部分子（夸克和胶子的统称）是渐进自由的。相对论重离子碰撞实现了物理学家们在实验室中创造一个小型宇宙大爆炸的愿望,使在实验室中对夸克胶子等离子体的形成及特性展开系统分析成为可能。从超级质子同步加速器（SPS）到相对论重离子对撞机（RHIC）,再到最新的大型强子对撞机（LHC）,物理学家们已经在不同的碰撞系统,不同的碰撞能量下对夸克胶子等离子体做了系统性的研究,但仍然存在诸多悬而未决的问题。高能部分子在穿越夸克胶子等离子体时受到强相互作用会损失部分能量,部分子然后经过碎裂（fragmentation）过程形成一个末态粒子喷注（jet）,由于QGP诱导入射部分子辐射胶子损失能量被称为喷注淬火（jetquenching）。RAA是高能物理实验上一个非常重要的观测量,它反应了部分子在穿越夸克胶子等离子体时能量损失的程度。在RAA的测... 

【文章来源】：华中师范大学湖北省 211工程院校 教育部直属院校

【文章页数】：156 页

【学位级别】：博士

【文章目录】：
摘要
Abstract
1 QGP and Relativistic Heavy Ion Collisions
    1.1 Standard Model of particle physics
    1.2 Quantum Chromodynamics
        1.2.1 QCD Lagrangian
        1.2.2 Asymptotic freedom
    1.3 Quark Gluon Plasma
        1.3.1 Lattice QCD predictions
        1.3.2 QCD phase diagram
    1.4 Relativistic Heavy Ion Collisions
2 Underlying Event
    2.1 Multiple parton interactions
    2.2 Monte Carlo models
        2.2.1 PYTHIA 8
        2.2.2 EPOS LHC
    2.3 Overview of UE measurements
        2.3.1 UE measurements at the RHIC
        2.3.2 UE measurements at the Tevatron
        2.3.3 UE measurements with ALICE detector
        2.3.4 UE measurements with ATLAS detector
        2.3.5 UE measurements with CMS detector
T">    2.4 Relative Transverse Activity Classifier,RT

3 The ALICE detector at the LHC
    3.1 The Large Hadron Collider（LHC）
    3.2 A Large Ion Collider Experiment
        3.2.1 ALICE detector layout
        3.2.2 Trigger system
        3.2.3 Offline framework
        3.2.4 Performance
4 UE activity leading track pr dependence
    4.1 Introduction
    4.2 Data sample
    4.3 Event and track selection criterion
    4.4 correction procedures
        4.4.1 Leading track misidentification
        4.4.2 Track contamination
        4.4.3 Tracking efficiency
        4.4.4 Vertex reconstruction
    4.5 Systematic uncertainty
        4.5.1 ITS-TPC track matching
        4.5.2 Track cuts
        4.5.3 Misidentification bias
        4.5.4 Strangeness bias
        4.5.5 Vertex reconstruction
        4.5.6 Monte-Carlo dependence
        4.5.7 Non closure in Monte-Carlo
    4.6 Results
T">        4.6.1 UE distributions versus leading p_T

        4.6.2 Charged particle dN/dη in the Transverse region
T dependence">5 UE activity R_T dependence
    5.1 Introduction
    5.2 Data sample
    5.3 Event and track selection criterion
    5.4 correction procedures
        5.4.1 Leading-track misidentification
        5.4.2 Track contamination
        5.4.3 Tracking efficiency
        5.4.4 Vertex reconstruction
    5.5 Unfolding and re-weight
        5.5.1 response matrix rebuilding
        5.5.2 Bayesian unfolding method
        5.5.3 Re-weight
    5.6 Systematical uncertainty
        5.6.1 ITS-TPC track matching efficiency
        5.6.2 Track cuts
        5.6.3 Monte Carlo dependence
        5.6.4 Non closure in Monte-Carlo
        5.6.5 vertex selection
        5.6.6 Number of tracks to the primary vertex
        5.6.7 Iterations
        5.6.8 Unfolding approach
    5.7 results
        5.7.1 Event probability distribution
">        5.7.2 Charged particle

6 Summary and outlook
Bibliography
List of publications and activities
论文中文简介
Acknowledgements



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