Unfolding the effects of final-state interactions and quantum statistics in two-particle angular correlations

TL;DR

This paper presents a Monte Carlo method to disentangle quantum statistics and final-state interaction effects in two-particle angular correlations in proton-proton collisions, revealing structures linked to strong interactions.

Contribution

The authors develop and validate a novel Monte Carlo approach to separate QS and FSI effects in angular correlations, enhancing understanding of underlying particle interactions.

Findings

Unfolded quantum statistics and FSI effects in angular correlations.

Identified strong interaction structures in baryon pairs.

Provided predictions for correlation modifications due to QS and FSI.

Abstract

Angular correlations of identified particles measured in ultrarelativistic proton-proton (pp) and heavy-ion collisions exhibit a number of features which depend on the collision system and particle type under consideration. Those features are produced by mechanisms, such as (mini)jets, elliptic flow, resonance decays, and conservation laws. In addition, of particular importance are those related to the quantum statistics (QS) and final-state interactions (FSIs). In this paper we show how to unfold the QS and FSI contributions in angular correlation functions by employing a Monte Carlo approach and using momentum correlations (femtoscopy), focusing on pp reactions. We validate the proposed method with PYTHIA 8 Monte Carlo simulations of pp collisions at $\sqrt{s}=13$ TeV coupled to calculations of QS and FSI effects with the Lednick\'y and Lyuboshitz formalism and provide predictions for the unfolded effects. In particular, we show how those effects modify the shape of the angular correlation function with emphasis on pions and protons. Most importantly, specific structures observed in the near-side region for both baryon-baryon and baryon-antibaryon pairs, originating from the strong interaction, are unveiled with the proposed method.