Measurement of long-range particle correlations in small systems with the ATLAS detector

TL;DR

This paper reviews recent ATLAS measurements of long-range particle correlations across different collision systems at the LHC, aiming to understand fluctuations in small systems by comparing results from pp, p+Pb, and Pb+Pb collisions.

Contribution

It presents new measurements of particle correlations in various collision systems at the LHC, highlighting differences and similarities to deepen understanding of fluctuations in small systems.

Findings

Correlations observed are consistent across different systems with same multiplicities.

Differences in initial geometries affect the correlation patterns.

Results contribute to understanding the origin of fluctuations in small collision systems.

Abstract

The study of particle correlations is an important instrument to understand the nature of relativistic heavy ion collisions. Using a wealth of new data available from the recent heavy ion runs of Large Hadron Collider at CERN it becomes possible to study particle correlations in different collisions systems under the same conditions. The results of several recent measurement performed by the ATLAS experiment are reviewed in this proceeding. Measurements are performed using various techniques in pp, p+Pb and Pb+Pb collisions at the energies $\sqrt{s}$, $\sqrt{s_{_{\rm{NN}}}}$ from 2.76 to 13 TeV. The results are compared between the systems having the same charged particle multiplicities in the final state, but different initial geometries. Results for multiplicity correlations, two-particle and muti-particle correlations measured in different techniques are presented and discussed. The goal of these complementary analyses is to further understanding the nature of fluctuations observed in small collision systems.