Multiplicity dependence of (multi-)strange baryons in the canonical ensemble with phase shift corrections

TL;DR

This paper investigates how (multi-)strange baryon production varies with charged particle multiplicity in high-energy collisions using an improved hadron resonance gas model that includes phase shift corrections for hadron interactions, emphasizing the importance of S-matrix formalism.

Contribution

It introduces a comprehensive model incorporating S-matrix corrections and global strangeness conservation to better describe multiplicity dependence of strange baryons in various collision systems.

Findings

S-matrix corrections improve yield predictions.

Global strangeness conservation better matches data.

Linear relation between charged hadrons and system volume.

Abstract

The increase in strangeness production with charged particle multiplicity, as seen by the ALICE collaboration at CERN in p-p, p-Pb and Pb-Pb collisions, is investigated in the hadron resonance gas model taking into account interactions among hadrons using S-matrix corrections based on known phase shift analyses. Strangeness conservation is taken into account in the framework of the canonical strangeness ensemble. A very good description is obtained for the variation of the strangeness content in the final state as a function of the number of charged hadrons in the mid-rapidity region using the same fixed temperature value as obtained in the most central Pb-Pb collisions. It is shown that the number of charged hadrons is linearly proportional to the volume of the system. For small multiplicities the canonical ensemble with local strangeness conservation restricted to mid-rapidity leads to a stronger suppression of (multi-)strange baryons than seen in the data. This is compensated by introducing a global conservation of strangeness in the whole phase-space which is parameterized by the canonical correlation volume larger than the fireball volume at the mid-rapidity. The results on comparing the hadron resonance gas model with and without S-matrix corrections, are presented in detail. It is shown that the interactions introduced by the phase shift analysis via the S-matrix formalism are essential for a better description of the yields data.