Strangeness from SPS to FAIR: Searching for the onset of deconfinement

Volker Friese,L Bravina,Y Foka,S Kabana

doi:10.1051/epjconf/201716406004

Volker Friese, L Bravina + Show 2 more

Open Access

https://doi.org/10.1051/epjconf/201716406004

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Abstract

Since the early days of heavy-ion physics, strangeness has been considered a sensitive probe of the state of matter created in nuclear collisions. This assessment still holds today, where we are witnessing renewed interest in collisions at moderate energies, manifested in the running or projected experimental programmes at RHIC, SPS, FAIR, and NICA. In this article, we will review the current understanding of strangeness production at lower energies and discuss how far future measurement of strange particles can contribute to understanding the properties of dense QCD matter and to the search for the onset of deconfinement.

Highlights

Nuclear matter, when sufficiently heated or compressed, is expected to undergo a transition to a deconfined state, where the degrees-of-freedom are not hadronic, but partonic
We will review the current understanding of strangeness production at lower energies and discuss how far future measurement of strange particles can contribute to understanding the properties of dense QCD matter and to the search for the onset of deconfinement
Yields of multi-strange hyperons are discriminative, and precision data on the Ξ and Ω yields as function of collision energy can be expected to lead to a definite conclusion on the issue. Such data can be expected from future experiments at NICA and FAIR-SIS300

Summary

Introduction

Nuclear matter, when sufficiently heated or compressed, is expected to undergo a transition to a deconfined state, where the degrees-of-freedom are not hadronic, but partonic. The properties of this state are currently being investigated in detail at the highest available collisions energies at the LHC. In parallel to these investigations of QCD matter at highest energies, a number of experimental programmes at lower, moderate collisions energies are proposed or already under way: the beam energy scan programme at RHIC, the NA61 experiment at the CERN-SPS, the CBM experiment at GSI-FAIR, and the MPD at JINR-NICA (the latter being facilities under construction). Varying the beam energy allows to a certain extent to study strongly interacting matter at different conditions This is illustrated, showing a speculative phase diagram of QCD matter.

The interest in strangeness

The onset of deconfinement

The φ meson

Strange anti-baryons

Summary