System size dependence of the hadronic rescattering effect at energies available at the CERN Large Hadron Collider

TL;DR

This study measures K*0 resonance production across various collision systems at the LHC to understand how hadronic rescattering effects depend on system size and multiplicity, revealing that these effects are primarily driven by particle multiplicity.

Contribution

It provides the first measurements of K*0 production in Xe-Xe collisions and compares them with other systems to explore system size dependence of hadronic rescattering effects.

Findings

Hadronic rescattering effects are independent of system size.

Resonance production depends mainly on charged-particle multiplicity.

Yields constrain the system size dependence of kinetic freeze-out temperature.

Abstract

The first measurements of $\mathrm{K^{*}(892)^{0}}$ resonance production as a function of charged-particle multiplicity in Xe$-$Xe collisions at $\sqrt{s_{\mathrm{NN}}}=$ 5.44 TeV and pp collisions at $\sqrt{s}=$ 5.02 TeV using the ALICE detector are presented. The resonance is reconstructed at midrapidity ($|y|< 0.5$) using the hadronic decay channel $\mathrm{K^{*0}} \rightarrow \mathrm{K^{\pm} \pi^{\mp}}$. Measurements of transverse-momentum integrated yield, mean transverse-momentum, nuclear modification factor of $\mathrm{K^{*0}}$, and yield ratios of resonance to stable hadron ($\mathrm{K^{*0}}$/K) are compared across different collision systems (pp, p$-$Pb, Xe$-$Xe, and Pb$-$Pb) at similar collision energies to investigate how the production of $\mathrm{K^{*0}}$ resonances depends on the size of the system formed in these collisions. The hadronic rescattering effect is found to be independent of the size of colliding systems and mainly driven by the produced charged-particle multiplicity, which is a proxy of the volume of produced matter at the chemical freeze-out. In addition, the production yields of $\mathrm{K^{*0}}$ in Xe$-$Xe collisions are utilized to constrain the dependence of the kinetic freeze-out temperature on the system size using the hadron resonance gas in partial chemical equilibrium (HRG-PCE) model.