$p_T$-dependent multiplicity fluctuations from PCA and initial conditions

Abstract

We present a Principal Component Analysis for a hydrodynamic simulation and compare with CMS experimental data. While the results are reasonable for anisotropic flow, for multiplicity fluctuations they are qualitatively different. We argue that this is due to too large transverse momentum ($p_T$) fluctuations and $N-p_T$ covariance in the simulation than seen experimentally. In turn this is related to too large initial size fluctuations.

References in corpus (13)

• Incident energy dependence of pt correlations at relativistic energies
• Transverse-momentum fluctuations in relativistic heavy-ion collisions from event-by-event viscous hydrodynamics
• Principal component analysis of event-by-event fluctuations
• Size fluctuations of the initial source and the event-by-event transverse momentum fluctuations in relativistic heavy-ion collisions
• Subleading harmonic flows in hydrodynamic simulations of heavy ion collisions
• Fluctuations of harmonic and radial flow in heavy ion collisions with principal components
• The mean transverse momentum of ultracentral heavy-ion collisions: A new probe of hydrodynamics
• Study of the sensitivity of observables to hot spot size in heavy ion collisions
• Principal-component analysis of two-particle azimuthal correlations in PbPb and pPb collisions at CMS
• Principal Component Analysis of collective flow in Relativistic Heavy-Ion Collisions
• $p_T$-Dependent Particle Number Fluctuations From Principal Component Analyses in Hydrodynamic Simulations of Heavy-Ion Collisions
• Principal component analysis of the nonlinear coupling of harmonic modes in heavy-ion collisions
• Measuring Momentum-Dependent Flow Fluctuations in Heavy-Ion Collisions