First mapping of the QCD critical surface in full (T, μ_B, μ_Q, μ_S) space via constant-entropy expansion gives a critical point at (114, 602) MeV in the pure baryon direction, with μ_B,c shifting 40-100 MeV in strangeness-neutral directions while remaining similar in charge-neutral ones.
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
9 Pith papers cite this work. Polarity classification is still indexing.
abstract
Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.
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A redefinition of the symmetry energy expansion that incorporates finite strangeness consistent with SU(3) flavor symmetry and remains valid beyond typical neutron-star central densities.
Models chemical non-equilibrium in finite-density QGP under conformal Gubser flow and its impact on hard thermal photon production, finding delayed equilibration with quarks lagging gluons, suppressed total yield but enhanced early high-pT photons, and distinct temporal emission structure.
NLED alters photon propagation near magnetars, producing ~10% errors in inferred radii via ray-tracing and a minimal ~350 ns travel-time delay.
In the random phase approximation, a convenient renormalization scheme for momentum-dependent meson self-energies shows that the moat regime extent in the QCD phase diagram depends critically on in-medium quark-meson interactions.
Dilepton yields in isospin-asymmetric QCD matter exhibit low-mass enhancement and a plateau in the pion-condensed phase, distinguishing it from chirally broken or restored phases.
A physics-informed neural network produces a thermodynamically consistent 4D equation of state for QCD matter that reproduces lattice QCD and hadron resonance gas results while extrapolating to high baryon density for use in hybrid hydrokinetic models.
UrQMD plus coalescence predicts measurable yields of hypernuclei such as 3_Lambda H, 4_Lambda H, Xi N and Xi NN in p+Au reactions at FAIR energies.
Recent net-proton cumulant ratios from RHIC BES-II data are compared to non-critical models from Lattice QCD, HRG, hydrodynamics and UrQMD, with volume fluctuation effects noted at fixed-target energies.
citing papers explorer
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QCD critical surface from constant entropy contours
First mapping of the QCD critical surface in full (T, μ_B, μ_Q, μ_S) space via constant-entropy expansion gives a critical point at (114, 602) MeV in the pure baryon direction, with μ_B,c shifting 40-100 MeV in strangeness-neutral directions while remaining similar in charge-neutral ones.
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Symmetry Energy Expansion with Strange Dense Matter
A redefinition of the symmetry energy expansion that incorporates finite strangeness consistent with SU(3) flavor symmetry and remains valid beyond typical neutron-star central densities.
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Finite-Density Dynamics of Chemically Equilibrating QGP in Conformal Gubser Flow and Hard Thermal Photon Production
Models chemical non-equilibrium in finite-density QGP under conformal Gubser flow and its impact on hard thermal photon production, finding delayed equilibration with quarks lagging gluons, suppressed total yield but enhanced early high-pT photons, and distinct temporal emission structure.
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Nonlinear electrodynamics in magnetars: systematic effects on radius constraints and timing analysis
NLED alters photon propagation near magnetars, producing ~10% errors in inferred radii via ray-tracing and a minimal ~350 ns travel-time delay.
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Dissecting the moat regime at low energies I: Renormalization and the phase structure
In the random phase approximation, a convenient renormalization scheme for momentum-dependent meson self-energies shows that the moat regime extent in the QCD phase diagram depends critically on in-medium quark-meson interactions.
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Dilepton Production as a Probe of Pion Condensation in Hot and Dense QCD Matter
Dilepton yields in isospin-asymmetric QCD matter exhibit low-mass enhancement and a plateau in the pion-condensed phase, distinguishing it from chirally broken or restored phases.
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Equation of State at High Baryon Densities from a Thermodynamically Informed Neural Network
A physics-informed neural network produces a thermodynamically consistent 4D equation of state for QCD matter that reproduces lattice QCD and hadron resonance gas results while extrapolating to high baryon density for use in hybrid hydrokinetic models.
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Hypernucleus production in p+Au reactions at the FAIR facility
UrQMD plus coalescence predicts measurable yields of hypernuclei such as 3_Lambda H, 4_Lambda H, Xi N and Xi NN in p+Au reactions at FAIR energies.
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Search for the QCD Critical Point in High Energy Nuclear Collisions: A Status Report
Recent net-proton cumulant ratios from RHIC BES-II data are compared to non-critical models from Lattice QCD, HRG, hydrodynamics and UrQMD, with volume fluctuation effects noted at fixed-target energies.