Angular correlation results from ALICE

TL;DR

This paper presents angular correlation measurements from ALICE to study jet modifications in heavy-ion collisions, providing insights into quark-gluon plasma properties and particle production mechanisms in different collision systems.

Contribution

It offers new angular correlation data from ALICE for Pb-Pb and pp collisions, enhancing understanding of jet-medium interactions and baseline particle production.

Findings

Jet properties are modified in Pb-Pb collisions, indicating interaction with the quark-gluon plasma.

Angular correlations in pp collisions serve as a baseline for heavy-ion studies.

Results contribute to understanding particle production mechanisms in small and large collision systems.

Abstract

In heavy-ion collisions, the quark-gluon plasma is expected to be produced, which is an almost perfect liquid that made up the Universe a few microseconds after the Big Bang. In these collisions, jets are also formed from hadronizing partons with high transverse momentum, and they traverse the hot and dense medium and interact with it. Their properties can be modified by these interactions, therefore these modifications, if present, can give insight into the properties of the plasma itself. Angular correlation measurements can be used to study jets in Pb-Pb collisions in a transverse momentum ($p_{\rm T}$) regime where jets are not easily reconstructable above the fluctuating background. Small collision systems (e.g., pp or p-Pb) can be used as reference for these measurements; however, these collisions themselves are of interest. For example, particle production mechanisms and conservation laws can be tested in these systems. Results from Pb-Pb and pp collisions recorded by the ALICE detector are presented in this paper.