Fluctuations of flow harmonics in Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$~TeV from the Glauber model

TL;DR

This paper uses the Glauber model with GLISSANDO 2 to analyze flow harmonic fluctuations in Pb+Pb collisions at 2.76 TeV, comparing results with experimental data and discussing initial eccentricity's relation to flow coefficients.

Contribution

It demonstrates that the Glauber model can reasonably reproduce flow harmonic fluctuations and their relation to initial eccentricities, providing computational tools for further analysis.

Findings

Reasonable agreement with experimental data for ellipticity and triangularity fluctuations.

The initial eccentricity is approximately proportional to the harmonic flow.

The model describes scaled standard deviation and F measure within a few percent for most centralities.

Abstract

In the framework of the Glauber model as implemented in GLISSANDO 2, we study the fluctuations of flow harmonics in Pb+Pb collisions at the LHC centre-of-mass energy of 2.76 TeV. The model with wounded nucleons and the admixture of binary collisions leads to reasonable agreement for the ellipticity and triangularity fluctuations with the experimental data from the ATLAS, ALICE, and CMS collaborations, verifying the assumption that the initial eccentricity is approximately proportional to the harmonic flow of charged particles. While the agreement, in particular at the level of event-by-event distributions of eccentricities/flow coefficients in not perfect, it leads to a fair (at the level of a few percent for all centralities except the most peripheral collisions) description of the scaled standard deviation and the F measure which involve the four-particle cumulants. We also discuss the case of quadrangular flow. Computer scripts that generate our results from the GLISSANDO 2 simulations are provided.