Regular Article - Theoretical Physics
Chiral spin symmetry and the QCD phase diagram
Institute of Physics, University of Graz, 8010, Graz, Austria
2 Institute for Theoretical Physics, Goethe University Frankfurt, Max-von-Laue-Str. 1, 60438, Frankfurt am Main, Germany
3 Physics Department, Brookhaven National Laboratory, 11973, Upton, NY, USA
Accepted: 27 November 2022
Published online: 15 December 2022
Lattice QCD simulations with chirally symmetric quarks have recently established approximate and symmetries of the quantum effective action in a temperature range above the chiral crossover , in which color-electric interactions between quarks dominate the dynamics. We show that such an intermediate temperature range between the chirally broken and plasma regimes is fully consistent with published screening mass spectra, which demonstrate the breakdown of thermal perturbation theory at the crossover between the partonic and the chiral spin symmetric regime at . From the known behavior of screening masses with baryon chemical potential, we deduce qualitatively how this chiral spin symmetric band extends into the QCD phase diagram. In the cold and dense region, we propose parity doubled baryons as possible candidates for chiral spin symmetric matter. This represents a special case of quarkyonic matter with confinement and restored chiral symmetry, and can smoothly transform to quark matter at sufficiently high densities. Finally, we discuss the potential of dilepton spectra to identify such matter forms.
© The Author(s) 2022
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