Multi-strange baryon production in Au+Au collisions at top RHIC energy as a probe of bulk properties

TL;DR

This paper presents STAR results on multi-strange baryon production in Au+Au collisions at RHIC, indicating the formation of a dense medium and partonic flow effects, with implications for understanding quark-gluon plasma.

Contribution

It provides new measurements of multi-strange baryons, their flow, and suppression patterns, highlighting early decoupling and partonic collectivity at RHIC.

Findings

Suppression of baryons at p_T>3 GeV/c supports dense medium formation.

Elliptic flow of multi-strange baryons suggests partonic level flow.

Spectra indicate early decoupling of multi-strange baryons.

Abstract

We report STAR preliminary results on multi-strange baryon production in Au+Au collisions at sqrt(s_NN)=200 GeV at RHIC. Its implication for the formation of a new state of matter is discussed. The system size dependence on the production of strange baryons is investigated to study the onset of strange quark equilibration in the medium. The nuclear modification factor of Lambda, Xi and Omega is also presented. Its suppression at p_T>3 GeV/c supports the formation of a dense interacting medium at RHIC. The spectra of multi-strange baryons reveal that within a hydro-inspired model, they may decouple prior than lighter particles and that their flow may be mostly developed at a partonic level. This idea is emphasized by the measurement of the v_2 of Xi+AntiXi and Omega+AntiOmega whose behaviour is close to the Lambda+AntiLambda baryon elliptic flow in the intermediate p_T region where a constituent quark scaling of v_2 is observed.