Long-range rapidity correlations in high energy AA collisions in Monte Carlo model with string fusion

TL;DR

This paper investigates long-range correlations in high-energy heavy-ion collisions using a Monte Carlo string-parton model with string fusion, revealing how correlations depend on collision centrality and string properties.

Contribution

It introduces a non-Glauber Monte Carlo model incorporating string fusion to study long-range correlations in Pb-Pb collisions at the LHC, highlighting the impact of centrality determination methods.

Findings

String fusion reduces n-n correlation coefficient with centrality.

Negative pt-n correlations are observed with effective centrality estimation.

pt-pt correlations are insensitive to centrality determination methods.

Abstract

The magnitude of long-range correlations between observables in two separated rapidity windows, proposed as a signature of the string fusion and percolation phenomenon, is studied in the framework of non-Glauber Monte Carlo string-parton model, based on the picture of elementary collisions of color dipoles. The predictions, obtained with and without string fusion, demonstrate effects of color string fusion on the observables in Pb-Pb collisions at the LHC: decrease of n-n correlation coefficient with centrality and negative pt-n correlations, if the sufficiently effective centrality estimator is applied. In general case it is shown that the values of n-n and pt-n correlation coefficients strongly depend on the method of collision centrality fixation. In contrast, the predictions obtained for pt-pt correlation have almost no effect of centrality determination method and the corresponding experimental data would produce the strong limitation on the transverse radius of a string.