Suppression and Azimuthal Anisotropy of Prompt and Non-prompt J/ψ in PbPb Collisions at √Snn =2.76 TeV in CMS
- 주제(키워드) Quarkonia , Heavy-ion collisions , Non-prompt J/psi , Prompt J/psi , The nuclear modification factor , The elliptic flow
- 발행기관 고려대학교 대학원
- 지도교수 홍병식
- 발행년도 2014
- 학위수여년월 2014. 8
- 학위구분 박사
- 학과 일반대학원 물리학과
- 세부전공 원자핵물리학 전공
- 원문페이지 116 p
- 실제URI http://www.dcollection.net/handler/korea/000000052746
- 본문언어 영어
- 제출원본 000045808933
초록/요약
The study of J/ψ production is one of the golden probes to understand properties of the Quark-Gluon-Plasma (QGP), which is a hot and dense medium produced in high energy heavy-ion collisions. In this thesis, the nuclear modification factor (R_{AA}) of prompt and non-prompt J/ψ and azimuthal anisotropy of prompt J/ψ are presented based on the pp and PbPb collision datasets which were taken in 2011 at center of mass energy 2.76 TeV, corresponding to 231 nb^{-1} and 150 μb^{-1} , respectively. From the nuclear modification factor, suppression of prompt J/ψ at p_{T} > 6.5 GeV/c by a factor of 5 and non-prompt J/ψ by a factor of 2.5 at head-on collisions are observed compare to the proton-proton collisions. Azimuthal anisotropy of prompt J/ψ is measured as 0.054 ± 0.013(stat.) ± 0.006(syst.) in 10-60% centrality region. While the nuclear modification factor of prompt and non-prompt J/ψ measurement shows strong centrality dependent suppression pattern, azimuthal anisotropy of prompt J/ψ does not have any centrality, rapidity or p_{T} dependent pattern.
more목차
1 Introduction
2 Theoretical Overview
2.1 Quantum Chromodynamics
2.1.1 QCD Lagrangian
2.1.2 Asymptotic Freedom and Confinement
2.2 The Quark-Gluon Plasma
2.2.1 Dynamics of Partons in the QGP
2.3 Quarkonia Production
2.3.1 Color Evaporation Model
2.3.2 Non-relativistic QCD
2.4 Non-prompt J/ψ Production
2.5 Geometry of Nucleus-Nucleus Collisions
2.5.1 Centrality
2.5.2 Glauber Model
3 The LHC Machine and the CMS Experiment
3.1 The Large Hadron Collider (LHC)
3.2 Compact Muon Solenoid (CMS)
3.2.1 Tracking System
3.2.2 Electromagnetic Calorimeter
3.2.3 Hadron Calorimeter
3.2.4 Muon System
3.2.5 Beam Scintillating Counter and Beam Pick-Up Timing
Experiment
4 Trigger System and Data Acquisition
4.1 Data Acquisition
4.2 Trigger System
4.2.1 Level-1 Trigger
4.2.2 High-Level Trigger
4.2.3 Muon Triggers in PbPb collisions
5 Muon Reconstruction
5.1 Muon Reconstruction in PbPb Collisions
5.1.1 Regional Iterative Tracking Algorithm
5.2 Dimuons in PbPb collisions
6 Offline Data Analysis
6.1 Event Selection
6.2 Reconstruction of Centrality in CMS
6.3 Monte Carlo Simulation
6.4 Define an Event-Plane
6.5 Muon Selection
6.5.1 Muon Quality Cut Variables
7 J/ψ Measurement in PbPb Collisions
7.1 Selected Kinematic Region of J/ψ Measurements
7.2 Inclusive J/ψ Signal Extraction
7.2.1 Systematic Uncertainty
7.3 Separation of Prompt and Non-Prompt J/ψ
7.3.1 The Pseudo-Proper Decay Length
7.3.2 Determination of Prompt and Non-Prompt J/ψ Components
7.3.3 Systematic Uncertainty
7.4 Efficiency
7.4.1 Data-driven efficiency
7.4.2 Systematic Uncertainty
7.4.3 Event-by-event Efficiency
8 Results
8.1 Nuclear Modification Factor
8.1.1 Systematic Uncertainties
8.1.2 Prompt and Non-prompt J/ψ R_{AA}
8.2 Elliptic Flow
8.2.1 Systematic Uncertainties
8.2.2 Prompt J/ψ v_{2}
9 Comparisons to Theory and Other Experiments
9.1 Nuclear Modification Factor
9.1.1 Non-prompt J/ψ
9.1.2 Prompt J/ψ
9.2 Elliptic Flow
10 Future Directions
10.1 L xy efficiency correction
A Appendix
A.1 1-Dimensional Projections of J/ψ Signal Fittings
A.1.1 PbPb collisions
A.2 List of N_{coll} , N_{part} and T_{AA} values