Fluctuations in ultra-relativistic heavy ion collisions

2017/02/03 by Aleksas Mazeliauskas, Mazeliauskas, Aleksas
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Nuclear Theory (nucl-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-th

paper · pdf · doi:10.48550/arxiv.1702.01202

205 pages, PhD dissertation

arxiv created 2017/02/03 · openalex publication_date 2017/02/03 · arxiv updated 2017/02/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Fluctuations are one of the main probes of the physics of the new state of hot and dense nuclear matter called the Quark Gluon Plasma (QGP) which is created in the ultra-relativistic heavy ion collisions. In this dissertation we extend and improve upon the existing descriptions of heavy ion collisions in three different directions: we study the new signatures of initial state fluctuations, the propagation of perturbations in the early stages of the collision, and the effect of thermal fluctuations on the hydrodynamic expansion of the QGP. First, we use Principal Component Analysis (PCA) to study event-by-event fluctuations in the spectrum of harmonic flow, v_n(p_T) for n=0--5, in hydrodynamic simulations of Pb+Pb collisions at the CERN Large Hadron Collider (√s_NN=2.76 \rm TeV). The PCA procedure finds two dominant contributions to the two-particle correlation function: the leading component is identified with the standard event plane v_n(p_T) and the subleading component is responsible for factorization breaking and reflects the radial excitation in the initial state. Second, we use leading order effective kinetic theory (accurate at weak coupling) to simulate the pre-equilibrium evolution of transverse energy and flow perturbations. We construct the linear response Green functions, which map initial perturbations to the energy momentum tensor at a time when hydrodynamics becomes applicable. Finally, we develop a set of kinetic equations for thermal noise correlators which are equivalent to nonlinear hydrodynamics with noise. We use the hydro-kinetic equations to analyze thermal fluctuations for a Bjorken expansion and determine the coefficient of the first fractional power (∝ 1/(τT)^3/2) of the nonlinear noise corrections to energy momentum tensor.

Citations

• The PHOBOS Glauber Monte Carlo
• Nonlinear Fluid Dynamics from Gravity
• Fate of non-Abelian plasma instabilities in3+1dimensions
• On the equivalence between the Boltzmann equation and classical field theory at large occupation numbers
• Nonstationary irreversible thermodynamics: A causal relativistic theory
• Viscosity in Strongly Interacting Quantum Field Theories from Black Hole Physics
• Initial state in heavy ion collisions
• Conservation of Isotopic Spin and Isotopic Gauge Invariance
• Partial-symmetries of weak interactions
• Light-Heavy Ion Collisions: A window into pre-equilibrium QCD dynamics?
• Review of Multibody Charm Analyses

Related

• Causal and Stable Relativistic Hydrodynamic Fluctuations
• Study of the hottest droplet of fluid through correlations and fluctuations of collective variables
• Initial State Fluctuations and Final State Correlations in Relativistic Heavy-Ion Collisions
• Fluctuations of harmonic and radial flow in heavy ion collisions with principal components
• Collision energy dependence in heavy ion collisions from nonlinear QCD evolution