Figures from paper submitted to Physical Review Letters

Abstract:

A suppression of the baryonic $Λ(1520)$ resonance yield relative to the $Λ$ ground state by $0.589 \pm 0.015^{\rm stat} \pm 0.086^{\rm syst}$ is observed in central relative to peripheral Pb-Pb collisions, with a significance of $6.8σ$. The $Λ(1520)$ production at midrapidity is measured in six centrality classes in Pb-Pb collisions for the first time at $\sqrt{s_{\rm NN}} = 5.02$ TeV with ALICE. The $Λ(1520)$ is a sensitive probe of late-stage hadronic interactions since its lifetime is comparable to that of the hadronic phase in heavy-ion collisions at the LHC. Statistical hadronization model calculations, predicting yields at chemical freeze-out, overestimate the measured ratio. The transverse-momentum spectra and the centrality dependence of the suppression are reproduced by the MUSIC hydrodynamic model only when coupled to the SMASH hadronic transport afterburner, which implements rescattering and regeneration in the late hadronic stage. The measurement, which represents the first observation of resonance suppression within a single collision system, provides a stringent test of the late-stage dynamics and evidence that hadronic interactions substantially modify reconstructible resonance yield.

e-Print: arXiv:2611.17010 | PDF | inSPIRE