Principal component analysis of event-by-event fluctuations

Abstract

We apply principal component analysis to the study of event-by-event fluctuations in relativistic heavy-ion collisions. This method brings out all the information contained in two-particle correlations in a physically transparent way. We present a guide to the method, and apply it to multiplicity fluctuations and anisotropic flow, using ALICE data and simulated events. In particular, we study elliptic and triangular flow fluctuations as a function of transverse momentum and rapidity. This method reveals previously unknown subleading modes in both rapidity and transverse momentum for the momentum distribution as well as elliptic and triangular flows.

arXiv comment6 pages, revised

References in corpus (34)

• A Multi-Phase Transport Model for Relativistic Heavy Ion Collisions
• Collective flow and viscosity in relativistic heavy-ion collisions
• Methods for analyzing anisotropic flow in relativistic nuclear collisions
• Hydrodynamic Modeling of Heavy-Ion Collisions
• Azimuthal anisotropy in Au+Au collisions at sqrtsNN = 200 GeV
• Transverse momentum analysis of collective motion in relativistic nuclear collisions
• Flow analysis with cumulants: direct calculations
• Flow analysis from multiparticle azimuthal correlations
• Elliptic flow from two- and four-particle correlations in Au + Au collisions at sqrt{s_{NN}} = 130 GeV
• System Size, Energy, Pseudorapidity, and Centrality Dependence of Elliptic Flow
• Measurement of the pseudorapidity and transverse momentum dependence of the elliptic flow of charged particles in lead-lead collisions at sqrt(s_NN) = 2.76 TeV with the ATLAS detector
• New method for measuring azimuthal distributions in nucleus-nucleus collisions
• The Importance of Correlations and Fluctuations on the Initial Source Eccentricity in High-Energy Nucleus-Nucleus Collisions
• Generic framework for anisotropic flow analyses with multi-particle azimuthal correlations
• Harmonic decomposition of two-particle angular correlations in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Effects of initial flow velocity fluctuation in event-by-event (3+1)D hydrodynamics
• Effect of flow fluctuations and nonflow on elliptic flow methods
• Measurement of higher-order harmonic azimuthal anisotropy in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV
• Momentum spectra, anisotropic flow, and ideal fluids
• Fluctuating flow angles and anisotropic flow measurements
• Eliminating experimental bias in anisotropic-flow measurements of high-energy nuclear collisions
• Hadron production in p+p, p+Pb, and Pb+Pb collisions with the HIJING 2.0 model at energies available at the CERN Large Hadron Collider
• Breaking of factorization of two-particle correlations in hydrodynamics
• Torqued fireballs in relativistic heavy-ion collisions
• Analysis of anisotropic flow with Lee-Yang zeroes
• Collective flow and long-range correlations in relativistic heavy ion collisions
• Non-flow correlations and elliptic flow fluctuations in gold-gold collisions at sqrt(s_NN)= 200 GeV
• Flow fluctuations and long-range correlations: elliptic flow and beyond
• Longitudinal fluctuations of the fireball density in heavy-ion collisions
• Effects of flow fluctuations and partial thermalization on $v_4$
• Suppression of high transverse momenta hadrons in Pb+Pb collisions at LHC
• Longitudinal fluctuations of the center of mass of the participants in heavy-ion collisions
• Hydro overview
• Decomposition of flow and nonflow in relativistic heavy-ion collisions

Cited by in corpus (53)

• Running the gamut of high energy nuclear collisions
• Hydrodynamic Approaches in Relativistic Heavy Ion Reactions
• Transverse momentum fluctuations and their correlation with elliptic flow in nuclear collision
• Transverse momentum-flow correlations in relativistic heavy-ion collisions
• Theoretical and Experimental Constraints for the Equation of State of Dense and Hot Matter
• Sensitivity of flow harmonics to sub-nucleon scale fluctuations in heavy ion collisions
• Cumulants and nonlinear response of high $p_T$ harmonic flow at $\sqrt{s_{NN}}=5.02$ TeV
• Event shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at $\sqrt{s_\rm{NN}}=2.76$ TeV
• Subleading harmonic flows in hydrodynamic simulations of heavy ion collisions
• Fluctuations of harmonic and radial flow in heavy ion collisions with principal components
• Systematic procedure for analyzing cumulants at any order
• Pre-hydrodynamic evolution and its signatures in final-state heavy-ion observables
• Hydrodynamic attractors in phase space
• Hydrodynamic flow amplitude correlations in event-by-event fluctuating heavy-ion collisions
• Measurement of forward-backward multiplicity correlations in lead-lead, proton-lead and proton-proton collisions with the ATLAS detector
• Forward-backward multiplicity fluctuation and longitudinal harmonics in high-energy nuclear collisions
• Study of the sensitivity of observables to hot spot size in heavy ion collisions
• Specific Heat of Matter Formed in Relativistic Nuclear Collisions
• Principal-component analysis of two-particle azimuthal correlations in PbPb and pPb collisions at CMS
• A flow paradigm in heavy-ion collisions
• Principal Component Analysis of collective flow in Relativistic Heavy-Ion Collisions
• Hydrodynamic modeling of pseudorapidity flow correlations in relativistic heavy-ion collisions and the torque effect
• $p_T$-Dependent Particle Number Fluctuations From Principal Component Analyses in Hydrodynamic Simulations of Heavy-Ion Collisions
• Estimating Elliptic Flow Coefficient in Heavy Ion Collisions using Deep Learning
• Applications of deep learning to relativistic hydrodynamics
• Principal components of nuclear mass models
• Two-particle correlations in pseudorapidity in a hydrodynamic model
• A simple model for rapidity fluctuations in the initial state of ultra-relativistic heavy-ion collisions
• Principal component analysis of the nonlinear coupling of harmonic modes in heavy-ion collisions
• Deep learning predicted elliptic flow of identified particles in heavy-ion collisions at the RHIC and LHC energies
• Measuring Momentum-Dependent Flow Fluctuations in Heavy-Ion Collisions
• Partial correlation analysis method in ultra-relativistic heavy-ion collisions
• Angle and magnitude decorrelation in the factorization breaking of collective flow
• Probing the structure of the initial state of heavy-ion collisions with $p_T$-dependent flow fluctuations
• Robustness of principal component analysis on harmonic flow in heavy ion collisions
• Rapidity dependence of transverse-momentum multiplicity correlations
• Estimation of initial state structures in high energy heavy-ion collisions using Principal Component Analysis (PCA)
• Principal Component Analysis of Azimuthal Flow in Intermediate-Energy Heavy-Ion Reactions
• Sub-leading flow modes in PbPb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV from HYDJET++ model
• Statistical analysis of pQCD energy loss across system size, flavor, $\sqrt{s_{NN}}$, and $p_T$
• Application of Principal Component Analysis to establish proper basis for flow studies in heavy-ion collisions
• Report from the A.I. For Nuclear Physics Workshop
• Momentum-dependent flow fluctuations as a hydrodynamic response to initial geometry
• Probing the transverse size of initial inhomogeneities with flow observables
• Forward-backward multiplicity correlations at the LHC from independent sources
• Jet momentum reconstruction in the QGP background with machine learning
• SPARKX: A Software Package for Analyzing Relativistic Kinematics in Collision Experiments
• Fluctuations in ultra-relativistic heavy ion collisions
• On feasibility of azimuthal flow studies with Principal Component Analysis
• Systematic study of flow vector fluctuations in $\sqrt{{\text{s}}_{{}_{\mathbf{NN}}}}=5.02$ TeV Pb-Pb collisions
• Mode-by-mode evolution of Pb-Pb collisions at 5.02 TeV in a hybrid model
• Searching for initial state fluctuations in heavy ion collisions at FAIR energy using Principal Component Analysis
• $p_T$-dependent multiplicity fluctuations from PCA and initial conditions