Production of Charge in Heavy Ion Collisions

TL;DR

This study analyzes charge-balance functions in heavy ion collisions, showing that a two-surge model with separate charge production phases better explains experimental data than a single-surge model.

Contribution

It introduces a two-surge model for charge production in heavy ion collisions, aligning with experimental data and lattice gauge theory predictions.

Findings

Two-surge model fits data better than single-surge model.

Charge separation occurs over different spatial rapidities for each surge.

First surge's charge production matches lattice gauge theory expectations.

Abstract

By analyzing preliminary experimental measurements of charge-balance functions from the STAR Collaboration at the Relativistic-Heavy-Ion Collider (RHIC), it is found that pictures where balancing charges are produced in a single surge, and therefore separated by a single length scale, are inconsistent with data. In contrast, a model that assumes two surges, one associated with the formation of a thermalized quark-gluon plasma and a second associated with hadronization, provides a far superior reproduction of the data. A statistical analysis of the model comparison finds that the two-surge model best reproduces the data if the charge production from the first surge is similar to expectations for equilibrated matter taken from lattice gauge theory. The charges created in the first surge appear to separate by approximately one unit of spatial rapidity before emission, while charges from the second wave appear to have separated by approximately a half unit or less.