Search For the Origin of the Away-side Double-humped Structure of jets in Heavy Ion Collisions

TL;DR

This paper presents a model explaining the double-humped away-side structure in di-hadron azimuthal correlations in heavy ion collisions, emphasizing the roles of transverse flow and initial parton distributions.

Contribution

The paper introduces a new model that accounts for the double-humped structure by incorporating transverse flow and initial parton spread, fitting data from RHIC collisions.

Findings

Transverse flow significantly influences the azimuthal correlation structure.

The initial spread of parton creation points and directions is crucial.

The model successfully reproduces experimental data across collision centralities.

Abstract

A model is constructed for the origin of the double-humped structure found in the di-hahron azimuthal correlation on the away-side in heavy ion collisions. The parameters in the model are determined by fitting $\Delta\phi$ azimuthal distribution in central Au+Au collisions at RHIC given by STAR collaboration when the trigger momentum is in $3-4\rm {GeV/c}$ and the associated particle momentum is in $1.3-1.8\rm{GeV/c}$. Then we apply our model to the semi-central and peripheral Au+Au collisions at RHIC and the responding $\triangle \phi$ azimuthal distribution are reproduced respectively. Our results show that the transverse flow effect plays an essential role in the experimentally observed di-hadron azimuthal distribution structure. The spread of the hard parton creation point and initial moving direction is also necessary for the double-humped structure.