Correlation between event multiplicity and elliptic flow parameter

TL;DR

This paper investigates the relationship between event multiplicity and elliptic flow parameter in high-energy collisions, using simulation models to analyze correlations and fluctuations in azimuthal particle distributions.

Contribution

It introduces a detailed analysis of multiplicity fluctuations and their impact on elliptic flow measurements using PACIAE and AMPT models.

Findings

Correlations between charge multiplicity and impact parameter are established.

Elliptic flow parameter shows dependence on multiplicity fluctuations.

Differences between event-wise and particle-wise averaging are discussed.

Abstract

The elliptic flow parameter (component), $v_2$, in the Fourier expansion of event-by-event charged particle multiplicity azimuthal distribution in the momentum space is studied by taking into account the multiplicity fluctuations. The correlations between charge multiplicity and impact parameter as well as between elliptic flow parameter and impact parameter (multiplicity) are investigated by both the parton and hadron cascade model PACIAE and a multiple phase transport model AMPT. A discussion is given for the event-wise average and particle-wise average in the definition of elliptic flow parameter.