<?xml version="1.0" encoding="UTF-8"?> <references> <reference> <a1>Scheid, Horst Sebastian</a1> <t1>On charm and beauty in dielectron measurements - Dielectron production in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV with ALICE</t1> <t2/> <sn/> <op/> <vo/> <ab>One possibility to study the quark-gluon plasma created in ultra-relativistic heavy-ion collisions is to measure modifications of an established baseline and by this infer on the interaction of a given probe with the created medium. A prominent way to introduce this baseline is through measurements in pp collisions. However, it is known that the binding effects of the proton in a heavy nucleus can modify said baseline without the creation of a quark-gluon plasma. In order to study such cold nuclear matter effects one can study collisions with a smaller transverse size and density, such as proton-lead (p-Pb) collisions. This thesis presents the analysis of dielectron production in p-Pb collisions at a collision energy in the centre of mass system of $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV as a function of the invariant mass and the momentum of the e+e- pair. The main purpose of the analysis is to study modifications with respect to scaling expectations of the contribution of heavy-flavour production and their impact on the measured dielectron yield. This is done by measuring the dielectron yield in p-Pb collisions and comparing it to baseline expectations. The baseline for light flavour hadron decays is constructed based on measurements in \ppb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV. The heavy-flavour contribution uses the measured production cross sections of heavy quarks in pp collisions and assumes a scaling of the production cross section with the number of binary nucleon-nucleon collisions. It is found that the baseline constructed in this way is able to describe the data within the experimental uncertainties. To investigate the impact of a possible modification of the contribution of the charm hadron decays to the dielectron spectrum, model calculations based on globally available data are included in the charm baseline. This reduces the expected contribution and a tension starts to arise in the mass region dominated by the heavy-flavour contributions. The possibility of an additional source of dielectrons produced as thermal radiation from a hot and dense medium formed in p-Pb collisions is investigated by also including such a source in the comparisons. The conclusion drawn from the presented measurement and its comparisons to baseline calculations under different assumptions is that no significant suppression of the charm contribution due to cold nuclear matter effects is present in the dielectron spectrum. However, it is possible that the suppression could be present but is offset due to the presence of a thermal source of dileptons, keeping the overall dilepton rate constant. The discussion finishes with an outlook on future measurements that might be able to resolve this ambiguity.</ab> <la>eng</la> <k1/> <pb/> <pp/> <yr>2024</yr> <ed/> <ul>http://cds.cern.ch/record/2918062/files/CERN-THESIS-2024-238.pdf; </ul> <no>Imported from Invenio.</no> </reference> </references>