Dependence of Ridge Formation on Trigger Azimuth: Correlated Emission Model

TL;DR

This paper presents a phenomenological model explaining how ridge formation in heavy-ion collisions depends on trigger azimuth, emphasizing the role of flow and semihard parton correlations, and reproduces experimental data across centralities.

Contribution

The Correlated Emission Model introduces a new framework linking trigger azimuth to ridge formation, successfully matching experimental observations with minimal parameters.

Findings

Reproduces ridge yield dependence on trigger azimuth for various centralities.

Proposes an inside-outside asymmetry function to analyze azimuthal correlations.

Provides insights into centrality dependence of ridge phenomena.

Abstract

Ridge formation in near-side correlation in heavy-ion collisions is studied in the framework of a phenomenological model, called Correlated Emission Model (CEM). Successive soft emissions due to jet-medium interaction lead to the enhancement of thermal partons which follow the local flow directions. The correlation between the flow direction and the semihard parton direction is the major factor that causes the ridge formation to depend on the trigger direction relative to the reaction plane. With the use of a few parameters we have been able to reproduce the data on the ridge yields as functions of the trigger azimuthal angle for different centralities. An inside-outside asymmetry function is proposed to further probe the characteristics of the azimuthal correlation function. Insights are provided for the understanding of some detailed aspects of the centrality dependence.