Systematic procedure for analyzing cumulants at any order

TL;DR

This paper introduces a systematic, flexible procedure for analyzing cumulants of any order in heavy-ion collisions, improving accuracy and ease of use over previous methods, with automatic corrections for detector effects.

Contribution

It generalizes existing cumulant analysis methods to arbitrary order, allowing for correlated particles in different phase-space windows and automatic detector correction.

Findings

Allows cumulant analysis at any order with a simple algorithm.

Automatically corrects for detector non-uniformity in azimuthal correlations.

Applicable to various phenomena like flow, correlations, and fluctuations.

Abstract

We present a systematic procedure for analyzing cumulants to arbitrary order in the context of heavy-ion collisions. It generalizes and improves existing procedures in many respects. In particular, particles which are correlated are allowed to belong to different phase-space windows, which may overlap. It also allows for the analysis of cumulants at any order, using a simple algorithm rather than complicated expressions to be derived and coded by hand. In the case of azimuthal correlations, it automatically corrects to leading order for detector non-uniformity, and it is useful for numerous other applications as well. We discuss several of these applications: anisotropic flow, event-plane correlations, symmetric cumulants, net baryon and net charge fluctuations.