Confined but chirally and chiral spin symmetric hot matter
arXiv:2410.13297 · doi:10.1140/epjc/s10052-025-14164-3
Abstract
We investigate properties of the quark--antiquark mesons at zero and finite temperature in the framework of a solvable chirally symmetric quark model with linear confining potential. The interquark interaction in the model is reminiscent of that derived in Coulomb gauge QCD, with the string tension being the only model parameter. We demonstrate that while the confining interaction induces spontaneous breaking of chiral symmetry at T=0, chiral symmetry gets restored at a temperature Tch ~ 90 MeV for the string tension fixed to provide the phenomenological value of the quark condensate. This temperature is similar to Tch ~ 130 MeV observed on the lattice in the chiral limit for N_c=3. The physical mechanism responsible for the chiral symmetry restoration in the confining regime is Pauli blocking of the quark levels, required for the existence of a nonvanishing quark condensate, by the thermal excitations of the quarks and antiquarks. Thus, above the chiral restoration temperature, the meson-like states are chirally symmetric and approximately chiral spin symmetric. A crucial property of the confined meson-like light-light states above Tch is their size that exceeds drastically that in the chirally broken phase below Tch, in contrast to the heavy-heavy mesons that nearly preserve their size irrespective of the temperature. This property is a result of Pauli blocking of the quark and antiquark levels with small momenta. Furthermore, the root-mean-square radius of the states with J=0,1 diverges in the chiral limit. This unexpected property must be a key to understanding unusual features of the hot QCD matter as observed at RHIC and LHC. Consequently, the confining but chirally symmetric matter above Tch can be considered as a dense system of very large and strongly overlapping meson-like states (``strings'').
arXiv comment23 pages; final version accepted by EPJC
References in corpus (33)
- QCD Phenomenology based on a Chiral Effective Lagrangian
- NJL-model analysis of dense quark matter
- Collective flow and viscosity in relativistic heavy-ion collisions
- From controversy to precision on the sigma meson: a review on the status of the non-ordinary resonance
- Coulomb Gauge QCD, Confinement, and the Constituent Representation
- Chiral phase transition temperature in (2+1)-Flavor QCD
- Variational solution of the Yang-Mills Schrödinger equation in Coulomb gauge
- Nature of the f_0(600) from its N_c dependence at two loops in unitarized Chiral Perturbation Theory
- Restoration of chiral and symmetries in excited hadrons
- Meson Structure in a Relativistic Many-Body Approach
- Symmetries of spatial meson correlators in high temperature QCD
- Chirally symmetric but confining dense and cold matter
- Aspects of the confinement mechanism in Coulomb-gauge QCD
- Symmetries of mesons after unbreaking of chiral symmetry and their string interpretation
- Two-dimensional QCD in the Coulomb gauge
- Isoscalar mesons upon unbreaking of chiral symmetry
- Chiral symmetry patterns of excited mesons with the Coulomb-like linear confinement
- SU(4) symmetry of the dynamical QCD string and genesis of hadron spectra
- Chiral-spin symmetry of the meson spectral function above
- Approximate degeneracy of spatial correlators in high temperature QCD
- Chiral spin symmetry and the QCD phase diagram
- Chiral symmetry breaking solutions for QCD in the truncated Coulomb gauge
- Vacuum replicas in QCD
- Pion spectral properties above the chiral crossover of QCD
- Mesonic states and vacuum replicas in potential quark models for QCD
- Chiral spin symmetry and hot/dense QCD
- Infrared stability of quarkyonic matter with the 1/p^4 confinement
- Pseudo-scalar meson spectral properties in the chiral crossover region of QCD
- Confined but chirally symmetric hadrons at large density and the Casher's argument
- How Chiral Symmetry Breaking Affects the Spectrum of the Light-Heavy Mesons in the 't Hooft Model
- Symmetries of meson correlators in high temperature QCD with physical domain-wall quarks
- Chiral symmetry restoration at finite temperature within the Hamiltonian approach to QCD in Coulomb gauge
- Quark running mass and vacuum energy density in truncated Coulomb gauge QCD for five orders of magnitude of current masses