Heavy-quark azimuthal momentum correlations as a sensitive probe of thermalization

TL;DR

This paper investigates how heavy-quark azimuthal momentum correlations can serve as sensitive indicators of thermalization in high-energy nuclear collisions, using PYTHIA simulations to analyze potential modifications in Pb+Pb collisions.

Contribution

It introduces a novel method using two-particle transverse momentum correlators applied to heavy-quark pairs to probe thermalization at the partonic level in heavy-ion collisions.

Findings

Correlations in p+p collisions at 14 TeV are characterized using PYTHIA.

Potential modifications of correlations in Pb+Pb collisions could signal thermalization.

The study proposes azimuthal momentum correlations as a sensitive probe for the QCD medium's thermalization.

Abstract

In high-energy nuclear collisions the degree of thermalization at the partonic level is a key issue. Due to their large mass, heavy quarks and their possible participation in the collective flow of the QCD-medium constitute a powerful probe for thermalization. We present studies with PYTHIA for p+p collisions at the top LHC energy of $\sqrt{s}$ = 14 TeV applying the two-particle transverse momentum correlator $<\Delta p_{t,1}, \Delta p_{t,2}>$ to pairs of heavy-quark hadrons and their semi-leptonic decay products as a function of their relative azimuth. Modifications or even the complete absence of initially existing correlations in Pb+Pb collisions might indicate thermalization at the partonic level.