On multiplicity correlations in the STAR data

TL;DR

This paper analyzes multiplicity correlations in STAR collision data, comparing experimental results with PYTHIA simulations and a superposition model, revealing limitations of the models in capturing centrality dependence.

Contribution

The study evaluates the effectiveness of PYTHIA and a superposition model in describing multiplicity correlations in STAR data, highlighting their respective strengths and shortcomings.

Findings

PYTHIA with default parameters fits pp data well

Superposition model fails to reproduce centrality dependence

Discussion of possible reasons for model discrepancies

Abstract

The STAR data on the multiplicity correlations between narrow psudorapidity bins in the pp and AuAu collisions are discussed. The PYTHIA 8.145 generator is used for the pp data, and a naive superposition model is presented for the AuAu data. It is shown that the PYTHIA generator with default parameter values describes the pp data reasonably well, whereas the superposition model fails to reproduce the centrality dependence seen in the data. Some possible reasons for this failure and a comparison with other models are presented.