Energy and System-Size Dependence of Long-Range Multiplicity Correlations from the STAR Experiment

TL;DR

This paper investigates how long-range multiplicity correlations vary with system size and energy in different collision systems, revealing potential signs of high-density matter formation in central heavy-ion collisions at high energies.

Contribution

It provides a systematic analysis of forward-backward multiplicity correlations across various systems and energies, highlighting the energy and system size dependence of these correlations.

Findings

Correlation strength remains constant in central A+A collisions at high energy.

Maximum correlations occur at midrapidity in peripheral and lower energy collisions.

Results suggest possible formation of high-density matter in central high-energy collisions.

Abstract

A discussion of results for short and long-range multiplicity correlations (forward-backward) are presented for several systems (Au+Au, Cu+Cu, and pp) and energies (e.g. $\sqrt{s_{NN}}$ = 200, 62.4, and $\approx$ 20 GeV). These correlations are measured with increasing values of a gap in pseudorapidity, from no gap at midrapidity to a separation of 1.6 units ($|\eta|$ = 0.8). For the highest energy, central A+A collisions, the forward-backward correlation strength maintains a constant value across the measurement region. In peripheral collisions, at lower energies, and in pp data, the maximum appears at midrapidity. This result may indicate the possible formation of high density matter for central A+A collisions at $\sqrt{s_{NN}}$ = 200 GeV.