Measuring differential flow angle fluctuations in relativistic nuclear collisions

TL;DR

This paper investigates flow angle fluctuations in relativistic nuclear collisions, demonstrating that four-subevents cumulant methods effectively reduce non-flow effects and enable accurate measurement of these fluctuations.

Contribution

It introduces and validates four-subevents cumulant methods to accurately quantify differential flow angle fluctuations, minimizing non-flow effects in the analysis.

Findings

Four-subevents cumulant methods reduce non-flow effects.

Flow angle fluctuation measurements are feasible with these methods.

Simulations with HIJING and AMPT models support the approach.

Abstract

Recently studies of the differential nature of the flow angle fluctuations, known as event plane angular decorrelation, indicated that measurements that assume a common symmetry plane may need to consider the flow angle fluctuations effect. Using the HIJING and AMPT models, it is shown that the flow angle fluctuations measurements, obtained with the two- and three-subevents correlation method, could have significant non-flow effects associated with long- and short-range non-flow correlations. The current study demonstrates the four-subevents cumulant methods' ability to reduce the non-flow effects. It is further argued that the measurements using the four-subevents correlation method can be used to provide accurate quantification of the differential flow angle fluctuations.