Narrow Results

The main goal of heavy-ion physics is to study the properties of the deconfined state of matter known as the Quark-Gluon Plasma (QGP) created in ultra-relativistic heavy-ion collisions. A systematic study of strangeness production is of fundamental importance for determining the thermal properties of the system created in such collisions. In the central barrel of the ALICE detector, K${}_s^0$, $\mathrm{\Lambda }$, $\mathrm{\Xi }$ and $\mathrm{\Omega }$ can be identified reconstructing their weak decay topology. It will be shown that the relative production (to pions) of strange particles follows a continuous increasing trend from low multiplicity pp to peripheral Pb–Pb collisions, above which a saturation is visible for central Pb–Pb collisions. This increasing trend is similar for pp and p–Pb collisions. Moreover, comparison of strange particle production in pp collisions at two different energies ($\sqrt{s}$ = 7 TeV and 13 TeV) will be used to demonstrate that the observed trend in multiplicity is also energy independent.

Studies of light hadron and nuclei production are fundamental to characterize the hot and dense fireball created in ultra-relativistic heavy ion collisions and to investigate hadronisation mechanisms at the LHC. Observables investigated as a function of the charged particle multiplicity in proton-proton and proton-lead collisions have shown features not expected and qualitatively similar to what has been observed in larger size colliding systems. The ALICE experiment, exploiting its excellent tracking and PID capabilities, has performed an extensive and systematic study of strange and non-strange hadrons, short-lived hadron resonances and light (anti-)(hyper-)nuclei. A critical overview of these results will be presented through comparison with the statistical hadronisation model.