Eccentricity is not the only source of elliptic flow fluctuations

TL;DR

This paper investigates various sources of event-by-event elliptic flow fluctuations in heavy-ion collisions, revealing that fluctuations beyond initial eccentricity, including quantum and hadronic effects, significantly influence flow measurements.

Contribution

The study identifies and quantifies multiple dynamical sources of elliptic flow fluctuations beyond initial eccentricity in heavy-ion collisions.

Findings

Fluctuations from quantum interactions and hadronization are negative.

Initial eccentricity fluctuations are a primary source of flow variability.

Other dynamical fluctuations significantly impact flow interpretation.

Abstract

Sources of event-by-event elliptic flow fluctuations in relativistic heavy-ion collisions are investigated in a multiphase transport model. Besides the well-known initial eccentricity fluctuations, several other sources of dynamical fluctuations are identified. One is fluctuations in initial parton configurations at a given eccentricity. Second is quantum fluctuations in parton interactions during system evolution. Third is fluctuations caused by hadronization and final-state hadronic scatterings. The magnitudes of these fluctuations are investigated relative to eccentricity fluctuations and average flow magnitude. The fluctuations from the latter two sources are found to be negative. The results may have important implications to the interpretation of elliptic flow data.