Possible signals of two QCD phase transitions at NICA-FAIR energies

K A Bugaev,A I Ivanytskyi,L V Bravina,D O Savchenko,B E Grinyuk,D B Blaschke,E E Zabrodin,S Kabana,E G Nikonov,G M Zinovjev,V V Sagun,A V Taranenko

doi:10.1051/epjconf/201920403001

Abstract

The chemical freeze-out irregularities found with the most advanced hadron resonance gas model and possible signals of two QCD phase transitions are discussed. We have found that the center-of-mass collision energy range of tricritical endpoint of QCD phase diagram is [9; 9.2] GeV which is consistent both with the QCD inspired exactly solvable model and experimental findings.

Highlights

The experimental programs of heavy ion collisions planned at RHIC (BNL) [1], NICA (JINR) [2] and FAIR (GSI) [3] are aimed to study the phase diagram of strongly interacting matter
We have found that the center-of-mass collision energy range of tricritical endpoint of quantum chromodynamics (QCD) phase diagram is [9; 9.2] GeV which is consistent both with the QCD inspired exactly solvable model and experimental findings
At the same time during last few years two theoretical groups, namely the Kiev and the Giessen ones, reported the signals of two QCD phase transitions (PTs), and, remarkably, they independently conclud√ed [7,8,9,10,11,12] that the chiral symmetry restoration (CSR) PT occurs in the hadronic phase at the center-of-mass collision energy sNN 4 − 5 G√eV, while the deconfinement PT to quark gluon plasma (QGP) occurs at the collision energy sNN 9 − 10 GeV

Summary

Introduction

The experimental programs of heavy ion collisions planned at RHIC (BNL) [1], NICA (JINR) [2] and FAIR (GSI) [3] are aimed to study the phase diagram of strongly interacting matter. At the same time during last few years two theoretical groups, namely the Kiev and the Giessen ones, reported the signals of two QCD PTs, and, remarkably, they independently conclud√ed [7,8,9,10,11,12] that the CSR PT occurs in the hadronic phase at the center-of-mass collision energy sNN 4 − 5 G√eV, while the deconfinement PT to quark gluon plasma (QGP) occurs at the collision energy sNN 9 − 10 GeV Both groups argued that the CSR is the first order PT [10,11,12], while the deconfinement PT has a second order [10,11,12,13] or a weak fiflcorusmctteuoartdotieoarnc[s1oa2nt]c.l√uMssiNooNrneothva8et.r8,thcGeoemcVoblliwinsiiintohgnttheheneehrrygepsyuorltathsnegoseifs[√o1f4s]NexNoinstteh8ne.c8ee−nohf9a.tn2wcoGemeQVeCncDtoorPfrTelsisgp,howtnendushcanlvoeeti to a vicinity of CEP as it was suggested in [14], but to a vicinity of 3CEP [12, 15].

HRGM with Multicomponent Hard-Core Repulsion

Hadronic Matter with CSR

Conclusions