Identified Two-particle Correlations and Quantum Number Conservations in p-p and Pb-Pb Collisions at LHC Energies

TL;DR

This study investigates quantum number conservation effects on two-particle correlations at high transverse momenta in p-p and Pb-Pb collisions at LHC energies, revealing distinct patterns and evolution with energy and multiplicity.

Contribution

It provides new insights into how quantum number conservation manifests in identified particle correlations across different collision systems and energies using Monte Carlo simulations.

Findings

Distinct splitting patterns observed in p-p and Pb-Pb collisions.

Splitting evolves smoothly with energy and multiplicity in p-p.

Different trends for kaons and protons in Pb-Pb collisions.

Abstract

In this paper we continue the investigation of the effect of quantum number conservations of pions, kaons, and protons, with very high transverse momenta (up to 25 GeV/c), during parton fragmentation and hadronization in p-p and Pb-Pb collisions at LHC energies. The strength of the conservation effects are studied by identified two-particle correlations in Monte Carlo generated events in the mid-rapidity region ($|\eta| < 1$). The simulated p-p events were generated with PYTHIA 8, using its main default settings, at $\sqrt{s}=200$~GeV, $\sqrt{s}=2.76$~TeV, $\sqrt{s}=7$~TeV, and $\sqrt{s}=14$~TeV. In parallel to this, HIJING 1.36 was used to generate Pb-Pb events at $\sqrt{s_{\rm NN}}=2.76$~TeV with centralities $0-10\%$, $30-40\%$ and $80-90\%$. The extracted identified associated hadron spectra for charged pion, kaon, and proton show identified trigger-hadron dependent splitting between oppositely charged associated particle species in any nucleus-nucleus collisions. The Pb-Pb data exhibits a peculiar splitting pattern as a function of the transverse momentum of the associated particle $p_{T,assoc}$ both on the near and away side that is different from the patterns observed in p-p collisions. The splitting shows smooth evolution with collision energy and event multiplicity in p-p collisions while in Pb-Pb collisions different trend were observed for kaons and protons.