A Comparison of p-p, p-Pb, Pb-Pb Collisions in the Thermal Model: Multiplicity Dependence of Thermal Parameters

International audienceAn analysis is made of the particle composition (hadrochemistry) of the final state in proton-proton (p-p), proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions as a function of the charged particle multiplicity (dNch/dη). The thermal model is used to determine the chemical freeze-out temperature as well as the radius and strangeness saturation factor γs. Three different ensembles are used in the analysis; namely, the grand canonical ensemble, the canonical ensemble with exact strangeness conservation, and the canonical ensemble with exact baryon number, strangeness, and electric charge conservation. It is shown that for high multiplicities (at least 20 charged hadrons in the midrapidity interval considered) the three ensembles lead to the same results