A measurement of neutral mesons inside jets in pp - collisions at 5TeV

Abstract

This thesis presents a study of jet production and the decay dynamics of neutral mesons (π 0 and η) within those jets in proton-proton collisions, utilizing data from the ALICE experiment at the LHC. Employing both EMC-EMC and PCM-EMC reconstruction methods, the research investigates the momentum- dependent invariant yields of these mesons across various jet transverse momen- tum (p T,jet ) ranges and explores the η/π 0 ratio to understand the underlying production mechanisms and their compatibility with theoretical models. The analysis reveals a marked agreement between the invariant yields within jets and minimum bias measurements for mesons with p T above the jet momen- tum threshold, validating QCD’s predictions on meson production rates. The study continues into the exploration of the η/π 0 ratio as a function of jet mo- mentum, providing critical insights into meson production dynamics within jets and indicating a nuanced understanding of nuclear modification factors in heavy- ion collisions. Through a segmented p T bin analysis, the research highlights the jet-momentum dependency of meson production, showcasing the functionality of alternative analysis methods such as the 2D-unfolding method and rotational background calculations, alongside offering a detailed comparison with prelimi- nary measurements. The findings contribute to our understanding of jet dynamics and meson pro- duction mechanisms in high-energy particle physics, offering valuable benchmarks for future theoretical and experimental studies in both pp and heavy-ion col- lisions. The thesis underscores the importance of re-evaluating existing particle reconstruction methods and detailed analytical techniques in an effort to enhance our comprehension of fundamental physics.