Forward-backward multiplicity correlations in the wounded nucleon model

TL;DR

This paper calculates forward-backward multiplicity correlations in nucleus-nucleus collisions using the wounded nucleon model, explaining recent experimental observations through wounded nucleon fluctuations.

Contribution

It extends the wounded nucleon model to arbitrary nucleus-nucleus collisions and interprets STAR data in terms of wounded nucleon number fluctuations.

Findings

Correlation strength grows with centrality.

Correlation strength is approximately flat in pseudorapidity for central collisions.

Fluctuations in wounded nucleon numbers explain observed correlation patterns.

Abstract

The forward-backward multiplicity correlation strength is calculated for arbitrary nucleus-nucleus collision in the framework of the wounded nucleon model. Discussion of our results in the context of the recent STAR data in Au+Au collisions at sqrt{s}=200 GeV is presented. It is suggested that the observed (i) growth of the correlation coefficient with centrality and (ii) approximately flat pseudorapidity dependence of the correlation strength for central collisions are due to the fluctuations of the number of wounded nucleons at a given centrality bin.