Two-particle angular correlations of identified particles in pp collisions at $\sqrt{s}$ = 13 TeV with ALICE

TL;DR

This paper investigates two-particle angular correlations of identified charged hadrons in 13 TeV proton-proton collisions, revealing unique short-range anticorrelation behaviors not predicted by existing models, to understand particle production mechanisms.

Contribution

It provides the first detailed study of identified hadron correlations at 13 TeV, analyzing multiplicity dependence and normalization methods to explore underlying physical phenomena.

Findings

Observed anticorrelation in short-range for baryon pairs

Differentiated correlation behaviors across particle types

Analyzed multiplicity dependence of correlations

Abstract

Two-particle angular correlation is one of the most powerful tools to study the mechanism of particle production in proton--proton (pp) collision systems by relating the difference between the azimuthal angle ($\Delta\varphi$) and the rapidity ($\Delta y$) of the particles from a pair. Hadronization processes are influenced by various physical phenomena, such as resonance decay, Coulomb interactions, laws of conservation of energy and momentum, and others, because of the quark content of the particles involved. Therefore, each correlation function is unique and shows a different dependence on transverse momentum $p_{\mathrm{T}}$ and/or multiplicity. The angular correlation functions reported by the ALICE Collaboration in pp collisions showed an anticorrelation in short range of ($\Delta y,\Delta\varphi$) for baryon pairs which is not predicted by any theoretical model.\\ \indent In this contribution, this behavior will be investigated by studying identified charged hadrons (i.e., $\pi^{\pm}$, $\rm K^{\pm}$, and p($\bar{\rm p}$)) in the $\Delta y,\Delta\varphi$ space in pp collisions at $\sqrt{s} = 13$ TeV recorded by ALICE. In addition, to distinguish the various physical contributions, collisions with different multiplicities are analyzed separately and diverse normalization methods are applied.