CERN Accelerating science

In this dissertation, the measurement of the prompt Lambda_c /D0 ratio as a function of multiplicity in p-Pb collisions at mid-rapidity at sqrt(sNN) = 5.02 TeV is discussed. By performing this measurement as a function of multiplicity in p-Pb collisions and by comparing to similar measurements in pp collisions, we can evaluate the pT-differential baryon to meson enhancement and relate it to results in e+e− and ep collisions, where lower Lambda_c /D0 ratios at low and intermediate pT have been observed. The origin of this discrepancy, which leads to the breakdown of the so-called factorization theorem for the elementary particle collisions, is still being debated. We aim to compare the p-Pb results not only to pp collisions to investigate the possible effects of cold nuclear matter, but to Pb-Pb collisions to study the impact of quark–gluon plasma formation on charm quark hadronization. This dissertation, aims to understand the charm quark hadronization in small systems by its evaluation as a function of system size. We also examine event generators alongside experimental data, both of which are essential to understanding the physics of interest and evaluate detector effects. Our goal is to investigate various models that implement different mechanisms of hadronization, to see where they match or differ from the data. In event generators, we have the ability to manipulate various parameters of the system’s dynamics, allowing us to isolate different effects and modes and understand their influence on the final observations. Such comparisons reveal whether we have accurately understood the physics of hadronization. Specifically, we discuss PYTHIA, a time dynamical event generator, and compare its performance against models that incorporate statistical and thermal approaches such as Statistical Hadronization Model (SHM), and Quark (re) Combination Model (QCM). We discuss how these models perform at explaining features of the transition of the system from pp to p-Pb and Pb-Pb.