# Calculating n-Point Charge Correlations in Evolving Systems

## TL;DR

This paper introduces a diagrammatic formalism to compute the time evolution of non-local charge correlations in dynamic systems, aiding the interpretation of charge fluctuation measurements in heavy-ion collisions.

## Contribution

It presents a novel diagrammatic approach to calculate evolving non-local charge correlations assuming local features are equilibrated.

## Key findings

- Provides a method to compute $n$-point charge correlations at different positions.
- Accounts for correlations involving up, down, and strange charges.
- Aims to interpret charge fluctuation data from the Relativistic Heavy-Ion Collider.

## Abstract

In dynamic systems, charge susceptibilities and local charge correlations change with time. These changes are accompanied by non-local correlations which spread diffusively with time and are constrained by local charge conservation. Assuming the local features of the correlation, which for a gas would be the correlation of charges within the same particle, are equilibrated, a diagrammatic formalism is presented for calculating the evolution of the associated non-local correlations. These provide correlations of $n$ density operators at different positions for arbitrary $n$. The techniques were developed with an eye towards relativistic heavy-ion collisions, and can account for correlations indexed by up, down and strange charges. Understanding the evolution of such correlations is crucial if one is to interpret measurements of charge fluctuations from the Relativistic Heavy-Ion Collider.