Energy dependence of Lambda and Xi production in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV measured at the CERN Super Proton Synchrotron

TL;DR

This paper investigates how the production of Lambda and Xi particles varies with collision energy in central Pb+Pb reactions at CERN SPS energies, comparing experimental results with theoretical models.

Contribution

It provides detailed measurements of strange baryon production across multiple energies and evaluates the performance of hadronic and statistical models in describing these results.

Findings

Statistical hadron gas models reasonably describe particle yields.

String hadronic models fail to match Xi multiplicities.

Energy dependence of spectra and yields is characterized.

Abstract

Results on $\Lambda$, $\bar{\Lambda}}$, $\Xi^{-}$, and $\bar{\Xi}^{+}$ production in central Pb+Pb reactions at 20A, 30A, 40A, 80A, and 158A GeV are presented. The energy dependence of transverse mass spectra, rapidity spectra, and multiplicities is discussed. Comparisons to string hadronic models (UrQMD and HSD) and statistical hadron gas models are shown. While the latter provide a reasonable description of all particle yields, the first class of models fails to match the $\Xi^{-}$, and $\bar{\Xi}^{+}$ multiplicities.