Symmetric cumulants and event-plane correlations in Pb+Pb collisions

TL;DR

This paper derives and tests approximate relations between symmetric cumulants and event-plane correlations in Pb+Pb collisions, improving agreement with experimental data and predicting unmeasured cumulants.

Contribution

It introduces approximate relations linking symmetric cumulants involving v4 and v5 to event-plane correlations, validated by hydrodynamic calculations.

Findings

Relations agree better with ALICE data than previous models.

Hydrodynamic calculations support the validity of the relations.

Predictions made for unmeasured symmetric cumulants.

Abstract

The ALICE Collaboration has recently measured the correlations between amplitudes of anisotropic flow in different Fourier harmonics, referred to as symmetric cumulants. We derive approximate relations between symmetric cumulants involving $v_4$ and $v_5$ and the event-plane correlations measured by ATLAS. The validity of these relations is tested using event-by-event hydrodynamic calculations. The corresponding results are in better agreement with ALICE data than existing hydrodynamic predictions. We make quantitative predictions for three symmetric cumulants which are not yet measured.