Strangeness Production in pp, p–Pb and Pb–Pb Collisions at the LHC Energies Measured with ALICE

D Colella

doi:10.1142/s2010194518600170

Abstract

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[Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] 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 ([Formula: see text] = 7 TeV and 13 TeV) will be used to demonstrate that the observed trend in multiplicity is also energy independent.

Highlights

Since the experimental observation[1,2] of the predicted[3] enhanced production of particles containing strange quark(s) in nucleus-nucleus with respect to proton-proton collisions, the study of strangeness production has a central role in heavy-ion physics
The Λ/K0S ratio as a function of pT and the multiplicity-differential strangeness production in the three colliding systems provided by the LHC and studied by ALICE will be presented
The Λ/K0s ratio has been measured in pp collisions at s = 7 TeV (divided in ten V0M event multiplicity classes from highest (I) to lowest (X) multiplicity) and in p-Pb collisions and are shown in figure

Summary

Introduction

Since the experimental observation[1,2] of the predicted[3] enhanced production of particles containing strange quark(s) in nucleus-nucleus with respect to (properly scaled) proton-proton collisions, the study of strangeness production has a central role in heavy-ion physics. In this paper the results on the strangeness production measurement will be shown and discussed in the context of collective phenomena and thermal production. This is an Open Access article published by World Scientific Publishing Company. Further distribution of this work is permitted, provided the original work is properly cited

Colella

Results

Conclusion