Investigating the mechanism of hadron production by measuring angular correlations of mesons with hidden strangeness in the ALICE experiment

Abstract

Hadronization is a process described by quantum chromodynamics in which hadrons are formed from quarks and gluons. Given the non-perturbative nature of this phenomenon, it is not yet fully understood. To study this effect, we can only use phenomenological models. Such phenomenological models are characterized by the fact that the parameters used to describe them are obtained from experimental data. Initial attempts to model this process in particle collisions can be found as early as 1977, but the study of this phenomenon continues to this day. The angular correlations are a powerful tool for studying the physics of heavy ions as well as lighter systems, such as protons. The correlations of the functions $\Delta \eta$ and $\Delta \varphi$ (the difference in pseudorapidity and azimuthal angle, respectively) are sensitive to contributions from various physical effects. The purpose of the analyses is to derive the influences of specific physical effects on the final angular correlation function. Using simulations, we have knowledge of what shapes in space ($\Delta \eta$, $\Delta \varphi$) we can expect from particular physical effects. In terms of its particle identification capabilities, the ALICE experiment is an ideal tool for performing correlation analyses for different particles. Following the extensive changes made to the ALICE experiment's detector system, it was necessary to introduce new data analysis software -- ALICE $O^2$. Along with the change in the analysis software, the format of the data and its processing have also changed. Thanks to the use of Appache Arrow flat arrays, declarative programming methods and the C++ 17 language, it allows for a reduction in the resources used and a speeding up of the analysis time. The existing research conducted in the field of angular correlations indicates that the process of hadronization of baryons may proceed differently from the process of meson production. This thesis intends to answer the question of whether mass affects the hadronization process by analyzing the angular correlations of mesons with similar mass to the lightest baryon, which is a proton