Estimating non-flow effects in measurements of directed flow of protons with the HADES experiment at GSI

TL;DR

This paper analyzes the centrality dependence of proton directed flow in Au+Au collisions at 1.23A GeV using the HADES experiment, focusing on non-flow effects and systematic uncertainties in flow measurements.

Contribution

It introduces a method to evaluate and quantify non-flow effects and detector biases in directed flow measurements at low energies.

Findings

Non-flow effects significantly influence flow measurements.

Systematic uncertainties are quantified across different rapidity regions.

Biases due to detector effects are effectively evaluated.

Abstract

Centrality dependence of the directed flow of protons in Au+Au collisions at the beam energy of 1.23A GeV collected by the HADES experiment at GSI is presented. Measurements are performed with respect to the spectators plane estimated using the Forward Wall hodoscope. Biases due to non-flow correlations and correlated detector effects are evaluated. The corresponding systematic uncertainties are quantified using estimates of the spectators plane from various forward rapidity regions constructed from groups of Forward Wall channels and protons reconstructed with the HADES tracking system.