Étude de la production des mésons charmés-étranges dans les collisions proton-proton et proton-plomb avec l'expérience ALICE au LHC

The study of the production of charm quarks in high-energy atomic-nucleus collisions offers an genuine approach for the study of the quark-gluon plasma. The understanding and characterisation of this state of deconfined-matter, at first sight created in heaviest systems, require a fine knowledge of lightest systems, such as proton-proton (pp) and proton-lead (p-Pb) collisions. In this manuscript, we present the measurement of the charm-strange mesons $\mathrm{D^{+}_{s}}$ ($\mathrm{c\overline{s}}$) production, at central rapidity, with the LHC run 2 data, collected in 2016 with the ALICE experiment. Two systems are studied: pp collisions at $\sqrt{s}=13$ TeV and p-Pb collisions at $\sqrt{s_{\text{NN}}}=5.02$ TeV. The production cross-section of $\mathrm{D^{+}_{s}}$, their relative abundance and their nuclear modification factor are measured then compared to other measurements and to various theoretical predictions. The p-Pb result establishes a new reference for the study of Pb-Pb collisions.