Measurement methods of radial flow in relativistic heavy-ion collisions

TL;DR

This paper compares two methods for measuring radial flow in relativistic heavy-ion collisions, demonstrating their effectiveness and establishing conditions for reliable estimates using a multiphase transport model.

Contribution

It introduces and validates two model-independent methods for extracting anisotropic radial flow from azimuthal distributions in heavy-ion collisions.

Findings

Both methods effectively estimate anisotropic radial flow.

The two-particle correlation method requires a minimum particle count per azimuthal bin.

The methods are validated using a multiphase transport model with string melting.

Abstract

Radial flow can be directly extracted from the azimuthal distribution of mean transverse rapidity. We apply the event-plane method and the two-particle correlation method to estimate the anisotropic Fourier coefficient of the azimuthal distribution of mean transverse rapidity. Using the event sample generated by a multiphase transport model with string melting, we show that both methods are effective. For the two-particle correlation method to be reliable, the mean number of particles in an azimuthal bin must be above a certain threshold. Using these two methods, anisotropic radial flow can be estimated in a model-independent way in relativistic heavy-ion collisions.