Effect of non-uniform efficiency on higher-order cumulants in heavy-ion collisions

TL;DR

This paper investigates how non-uniform detector efficiency affects the accuracy of higher-order cumulant measurements in heavy-ion collisions, proposing an averaged efficiency correction method supported by analytical and simulation results.

Contribution

It introduces a systematic approach to correct for non-uniform efficiency effects in cumulant analysis, demonstrating the effectiveness of averaged efficiency correction.

Findings

Averaged efficiency accurately reproduces true cumulants within each phase space.

Using averaged efficiency significantly reduces statistical uncertainties.

Careful phase space analysis is necessary when applying this correction method.

Abstract

We perform a systematic study on the effect of non-uniform track efficiency correction in higher-order cumulant analysis in heavy-ion collisions. Through analytical derivation, we find that the true values of cumulants can be successfully reproduced by the efficiency correction with an average of the realistic detector efficiency for particles with the same charges within each single phase space. The theoretical conclusions are supported by a toy model simulation by tuning the non-uniformity of the efficiency employed in the track-by-track efficiency correction method. The valid averaged efficiency is found to suppress the statistical uncertainties of the reproduced cumulants dramatically. Thus, usage of the averaged efficiency requires a careful study of phase space dependence. This study is important for carrying out precision measurements of higher-order cumulants in heavy-ion collision experiments at present and in future.