Ks, Lambda and Xi production at intermediate to high pT from Au+Au collisions at \sqrt{s_{NN}} = 39, 11.5 and 7.7 GeV

TL;DR

This study examines how the production of strange baryons and mesons varies with transverse momentum in gold-gold collisions at different energies, revealing changes in the created matter's properties at lower energies.

Contribution

It provides the first detailed comparison of nuclear modification factors and baryon/meson ratios at these specific collision energies, highlighting energy-dependent differences in the produced matter.

Findings

Baryon/meson separation at 39 GeV

Suppression of Ks at 39 GeV

Reduced baryon enhancement at 11.5 and 7.7 GeV

Abstract

We report on the pT dependence of nuclear modification factors ($R_{CP}$) for Ks, Lambda, Xi and the Anti-Lambda/Ks ratios at mid-rapidity from Au+Au collisions at \sqrt{s_{NN}} = 39, 11.5 and 7.7 GeV. At \sqrt{s_{NN}} = 39 GeV, the $R_{CP}$ data shows a baryon/meson separation at intermediate pT and a suppression for Ks for pT up to 4.5 GeV/$c$; the Anti-Lambda/Ks shows baryon enhancement in the most central collisions. However, at \sqrt{s_{NN}} = 11.5 and 7.7 GeV, $R_{CP}$ shows much less baryon/meson separation and Anti-Lambda/Ks shows almost no baryon enhancement. These observations indicate that the matter created in Au+Au collisions at \sqrt{s_{NN}} = 11.5 or 7.7 GeV might be distinct from that created at \sqrt{s_{NN}} = 39 GeV.