Recent selected theory developments for NICA

Abstract

Abstract. In this contribution I present a few selected topics of recent theoretical developments of relevance for the NICA facility under construction. In a first part, I discuss new aspects of the QCD phase diagram like the possible existence of a critical endpoint of first-order phase transitions from the perspective of generalizations of the 3-flavor PNJL model including the conjecture of a universal pressure for the onset of deconfinement in heavy-ion collisions and astrophysics. A second part is devoted to first results of the newly constructed event simulator (THESEUS) which is based on the particlization of the former three-fluid hydrodynamics code by Ivanov, Russkikh and Toneev that allows also to study the role of hadronic final state interactions. Possible signals of the mixed phase accessible at NICA are considered. In particular, the robustness of the baryon-stopping signal of deconfinement and the occurrence of antiflow for protons have been investigated for Au+Au collisions in the range of the NICA-MPD energy scan for √ s ∼ 6 . . . 8 GeV. This signal is reflected also in the flow pattern of light nuclear clusters, in particular deuterons. The sharp peak for the K + /π + ratio at √ s ∼ 8 GeV (the "horn" effect) is not obtained in the present version of THESEUS and calls for improvement of the equation of state input. I report the recent progress in developing a generalized Beth-Uhlenbeck approach to a unified description of quark-hadron matter which includes now strangeness and reveals a new mechanism for explaining the K + /π + ratio due to the pronounced occurrence of an anomalous mode in the K + at finite baryochemical potentials.

Mesons and diquarks in a color superconducting regime

“…In other words, the PNJL description may extrapolate LQCD data at finite densities. For these reasons, the PNJL model appears as an important tool to describe the color superconducting regime [38]. Moreover, in order to improve the reliability of this extrapolation, it has been proposed some improvements recently.…”

“…, in order to add , η η′ and the kaons in the description. Furthermore, since the PNJL model seems to become a standard in such calculations [38], the established equations should be able to take into account the inclusion of the Polyakov loop.…”

Phase diagram of strongly interacting matter: the last 20 years at the CERN SPS

“…He was the key organizer of CPOD 2010 Workshop in JINR, Dubna and CPOD 2016 Workshop in Wroclaw. Very importantly, David enthusiastically creates the physics programme of NICA -the new heavy-ion facility in JINR, Dubna [51,52]. I wish David to continue running his Universe for many years to come.…”