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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Precision Measurement of (Net-)proton Number Fluctuations in Au+Au Collisions at RHIC
11 Pith papers cite this work. Polarity classification is still indexing.
abstract
We report precision measurements on cumulants ($C_{n}$) and factorial cumulants ($\kappa_{n}$) of (net-)proton number distributions up to fourth-order in Au+Au collisions from phase II of the Beam Energy Scan program at RHIC. (Anti-)protons are selected at midrapidity ($|y|<0.5$) within a transverse momentum range of $0.4 < p_T < 2.0$ GeV/$c$. The collision energy and centrality dependence of these cumulants are studied over center-of-mass energies $\sqrt{s_{NN}}$ = 7.7 -- 27 GeV. Relative to various non-critical-point model calculations and peripheral collision 70-80\% data, the net-proton $C_4/C_2$ measurement in 0-5\% collisions shows a minimum around 19.6 GeV for significance of deviation at $\sim2$ -- $5\sigma$. In addition, deviations from non-critical baselines around the same collision energy region are also seen in proton factorial cumulant ratios, especially in $\kappa_2/\kappa_1$ and $\kappa_3/\kappa_1$. Dynamical model calculations including a critical point are called for in order to understand these precision measurements.
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SAM-3.0 derives canonical cumulants from grand-canonical joint cumulants via a closed recursion with multivariate partial exponential Bell polynomials for arbitrary numbers of conserved charges and observables.
The pion emission source in Au+Au collisions is tilted with magnitude decreasing rapidly as collision energy rises from 7.7 to 27 GeV, indicating departure from longitudinal boost invariance.
Including Fierz-complete four-quark interactions in fRG-QCD shifts the predicted critical endpoint to (T, μ_B) = (102, 647) MeV and slightly increases the phase boundary curvature to κ₂ = 0.0151, while confirming σ and π channels dominate except near the CEP.
Finite current relaxation introduces memory effects that suppress, shift, and reshape non-monotonic cumulant behavior relative to instantaneous equilibrium and Fickian diffusion, most visibly in higher-order cumulants.
JAM model simulations with the new CIGAR framework compute proton cumulants at √sNN = 3.2-4.5 GeV as a non-critical baseline for QCD critical point searches.
fRG calculations show the jet quenching parameter hat q is enhanced above the chiral boundary and peaks near the QCD critical end point due to critical sigma fluctuations.
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.
Hybrid model constrains STAR intermittency data to small, nearly energy-independent critical-like fractions, indicating limited critical-point contribution.
The MUSES Calliope engine computes multi-dimensional QCD equations of state, merges them consistently, and feeds them into viscous hydrodynamic simulations of heavy-ion collisions with movable critical points and critical scaling in transport coefficients.
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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Subensemble Acceptance Method 3.0: General Corrections to Cumulants from Exact Conservation Constraints
SAM-3.0 derives canonical cumulants from grand-canonical joint cumulants via a closed recursion with multivariate partial exponential Bell polynomials for arbitrary numbers of conserved charges and observables.
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Tilted geometry of the pion emission source in Au+Au collisions in the RHIC Beam Energy Scan
The pion emission source in Au+Au collisions is tilted with magnitude decreasing rapidly as collision energy rises from 7.7 to 27 GeV, indicating departure from longitudinal boost invariance.
-
Fierz-complete four-quark interactions and the QCD phase diagram
Including Fierz-complete four-quark interactions in fRG-QCD shifts the predicted critical endpoint to (T, μ_B) = (102, 647) MeV and slightly increases the phase boundary curvature to κ₂ = 0.0151, while confirming σ and π channels dominate except near the CEP.
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Cumulant dynamics in finite-memory diffusion
Finite current relaxation introduces memory effects that suppress, shift, and reshape non-monotonic cumulant behavior relative to instantaneous equilibrium and Fickian diffusion, most visibly in higher-order cumulants.
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Proton High-Order Cumulants in Au+Au Collisions at High Baryon Density from JAM with a Centrality-Independent Framework
JAM model simulations with the new CIGAR framework compute proton cumulants at √sNN = 3.2-4.5 GeV as a non-critical baseline for QCD critical point searches.
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Functional renormalization group study of the jet quenching parameter near the QCD critical end point
fRG calculations show the jet quenching parameter hat q is enhanced above the chiral boundary and peaks near the QCD critical end point due to critical sigma fluctuations.
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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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Understanding the Intermittency Signal in RHIC-STAR Data through Modeling
Hybrid model constrains STAR intermittency data to small, nearly energy-independent critical-like fractions, indicating limited critical-point contribution.
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Studying the QCD Matter produced in Heavy-Ion Collisions using the MUSES Calculation Engine
The MUSES Calliope engine computes multi-dimensional QCD equations of state, merges them consistently, and feeds them into viscous hydrodynamic simulations of heavy-ion collisions with movable critical points and critical scaling in transport coefficients.
- High-order fluctuations of temperature in hot QCD matter