Growth of Long Range Forward-Backward Multiplicity Correlations with Centrality in Au+Au Collisions at $\sqrt{s_{NN}}$ = 200 GeV

TL;DR

This study measures forward-backward multiplicity correlations in Au+Au and p+p collisions at 200 GeV, revealing that central collisions exhibit strong long-range correlations consistent with models involving multiple parton interactions.

Contribution

It provides the first detailed measurement of how correlation strengths vary with centrality in Au+Au collisions at 200 GeV, supporting models like DPM and CGC for long-range correlations.

Findings

Strong long-range correlations in central Au+Au collisions.

Correlation strength decreases with decreasing centrality.

Qualitative agreement with DPM and CGC predictions.

Abstract

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au+Au and $\textit{p+p}$ collisions at $\sqrt{s_{NN}}$ = 200 GeV. Strong short and long range correlations (LRC) are seen in central Au+Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short range correlations are observed in peripheral Au+Au collisions. Both the Dual Parton Model (DPM) and the Color Glass Condensate (CGC) predict the existence of the long range correlations. In the DPM the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC longitudinal color flux tubes generate the LRC. The data is in qualitative agreement with the predictions from the DPM and indicates the presence of multiple parton interactions.