The Interplay of Femtoscopic and Charge-Balance Correlations

TL;DR

This paper investigates how femtoscopic correlations and charge-balance correlations, which operate over different momentum scales, influence each other in heavy ion collision data analysis.

Contribution

It provides a quantitative analysis of the mutual distortion between femtoscopic and charge-balance correlations in high-energy nuclear collisions.

Findings

Charge-balance correlations extend over hundreds of MeV/c.

Final-state interactions mainly affect small relative momenta.

Correlations from both sources can distort each other's interpretation.

Abstract

Correlations driven by the constraints of local charge conservation have been shown to provide insight into the chemical evolution and diffusivity of the high-temperature matter created in ultra-relativistic heavy ion collisions. Two-particle correlations driven by final-state interactions have allowed the extraction of critical femtoscopic space-time information about the expansion and dissolution of the same collisions. Whereas correlations from final-state interactions mainly appear at small relative momenta, a few tens of MeV/$c$, charge-balance correlations extend over a range of hundreds of MeV/$c$. In nearly all previous analyses, this separation of scales is used to focus solely on one class or the other. The purpose of this study is to quantitatively understand the degree to which correlations from final-state interactions distort the interpretation of charge-balance correlations and vice versa.