Study of Angular Correlations in Monte Carlo Simulations in Pb-Pb Collisions

Balázs Endre Szigeti,Monika Varga-Kofarago

doi:10.3390/universe5050097

Abstract

In two-particle angular correlation measurements, the distribution of charged hadron pairs are evaluated as a function of pseudorapidity ( Δ η ) and azimuthal ( Δ φ ) differences. In these correlations, jets manifest themselves as a near-side peak around Δ η = 0 , Δ φ = 0 . These correlations can be used to extract transverse momentum ( p T ) and centrality dependence of the shape of the near-side peak in Pb-Pb collision. The shape of the near-side peak is quantified by the variances of the distribution. The variances are evaluated from a fit combining the peak and the background. In this contribution, identified and unidentified angular correlations are shown from Pb-Pb collisions at s N N = 2.76 TeV from Monte Carlo simulations (AMPT, PYTHIA 8.235/Angantyr). Results show that transport models in AMPT give better results than PYTHIA 8.235/Angantyr when comparing to the experimental results of the ALICE collaboration.

Highlights

In heavy-ion collisions, for processes where the typical momentum transfer is large ( Q >> ΛQCD )partons with high transverse momentum (p T ) are produced
Results show that transport models in AMPT give better results than PYTHIA 8.235/Angantyr when comparing to the experimental results of the ALICE collaboration
A new heavy-ion simulation model has been built on PYTHIA 8.235, called Angantyr

Summary

Introduction

In heavy-ion collisions, for processes where the typical momentum transfer is large ( Q >> ΛQCD )partons with high transverse momentum (p T ) are produced. Since the partons carry color charge, they can not exist freely [1] at low energies For this reason they eventually hadronize into a shower of correlated hadrons called jets. These jets are produced in the early stage of the collisions and propagate through the Quark-Gluon Plasma. During the propagation they interact with the hot and dense medium and lose momentum due to a chain of elementary processes, for instance induced gluon radiation and elastic scattering. These processes are jointly referred to as jet quenching [2]

Methods

Results

Conclusion