Circumstantial evidence for a soft nuclear symmetry energy at supra-saturation densities

Abstract

Within an isospin- and momentum-dependent hadronic transport model it is shown that the recent FOPI data on the ${\pi }^{-}/{\pi }^{+}$ ratio in central heavy-ion collisions at SIS/GSI energies (Willy Reisdorf {\it et al.}, NPA {\bf 781}, 459 (2007)) provide circumstantial evidence suggesting a rather soft nuclear symmetry energy \esym at $\rho \ge 2{\rho }_0$ compared to the Akmal-Pandharipande-Ravenhall prediction. Some astrophysical implications and the need for further experimental confirmations are discussed.

Version to appear in Phys. Rev. Lett

References in corpus (5)

• Recent Progress and New Challenges in Isospin Physics with Heavy-Ion Reactions
• Neutron and Proton Transverse Emission Ratio Measurements and the Density Dependence of the Asymmetry Term of the Nuclear Equation of State
• Systematics of pion emission in heavy ion collisions in the 1A GeV regime
• Isospin-dependent properties of asymmetric nuclear matter in relativistic mean-field models
• Neutron star properties and the equation of state of neutron-rich matter

Cited by in corpus (208)

• Equations of state for supernovae and compact stars
• Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. XII: Stiffness and stability of neutron-star matter
• Skyrme-Hartree-Fock-Bogoliubov nuclear mass formulas: Crossing the 0.6 MeV threshold with microscopically deduced pairing
• A way forward in the study of the symmetry energy: experiment, theory, and observation
• Results of the ASY-EOS experiment at GSI: The symmetry energy at suprasaturation density
• Symmetry energy from elliptic flow in 197Au + 197Au
• Higher-order effects on the incompressibility of isospin asymmetric nuclear matter
• Towards Understanding Astrophysical Effects of Nuclear Symmetry Energy
• Nucleon Effective Masses in Neutron-Rich Matter
• Neutron skin thickness in droplet model with surface width dependence: indications of softness of the nuclear symmetry energy
• Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. XI: Stabilizing neutron stars against a ferromagnetic collapse
• Systematics of central heavy ion collisions in the 1A GeV regime
• Probing high-density behavior of symmetry energy from pion emission in heavy-ion collisions
• Constraining the nuclear matter equation of state around twice saturation density
• Nuclear symmetry energy and its density slope at normal density extracted from global nucleon optical potentials
• Probing the Symmetry Energy with the Spectral Pion Ratio
• Combined Constraints on the Equation of State of Dense Neutron-Rich Matter from Terrestrial Experiments and Observations of Neutron Stars
• Constraining the High-Density Behavior of Nuclear Symmetry Energy with the Tidal Polarizability of Neutron Stars
• Comparison of heavy-ion transport simulations: Collision integral in a box
• Constraints on Nuclear Symmetry Energy Parameters
• Extracting Nuclear Symmetry Energies at High Densities from Observations of Neutron Stars and Gravitational Waves
• Bayesian Inference of High-density Nuclear Symmetry Energy from Radii of Canonical Neutron Stars
• Super-soft symmetry energy encountering non-Newtonian gravity in neutron stars
• Probing the Nuclear Symmetry Energy with Heavy Ion Collisions
• Comparison of heavy-ion transport simulations: Collision integral with pions and $\Delta$ resonances in a box
• Subthreshold pion production within a transport description of central Au+Au collisions
• Towards a model-independent constraint of the high-density dependence of the symmetry energy
• Dynamics of clusters and fragments in heavy-ion collisions
• Nuclear matter fourth-order symmetry energy in the relativistic mean field models
• Influence of Transport Variables on Isospin Transport Ratios
• Phase transitions in dense matter and the maximum mass of neutron stars
• Half-Skyrmions, Tensor Forces and Symmetry Energy in Cold Dense Matter
• The impact of energy conservation in transport models on the ${\pi }^{-}/{\pi }^{+}$ multiplicity ratio in heavy-ion collisions and the symmetry energy
• Comparison of Heavy-Ion Transport Simulations: Mean-field Dynamics in a Box
• Sensitivity of the transverse flow towards symmetry energy
• Neutron-proton elliptic flow difference as a probe for the high density dependence of the symmetry energy
• Probing the neutron skin with ultrarelativistic isobaric collisions
• On the Maximum Mass of Neutron Stars
• Nuclear Equation of state for Compact Stars and Supernovae
• Symmetry energy of cold nucleonic matter within a relativistic mean field model encapsulating effects of high momentum nucleons induced by short-range correlations
• Why is the nuclear symmetry energy so uncertain at supra-saturation densities?
• The Present and Future of QCD
• Magnetic effects in heavy-ion collisions at intermediate energies
• Symmetry energy investigation with pion production from Sn+Sn systems
• Nuclear Symmetry Energy Extracted from Laboratory Experiments
• Nuclear in-medium effects and collective flows in heavy-ion collisions at intermediate energies
• Probing neutron-proton dynamics by pions
• Elliptic flow and the symmetry energy at supra-saturation density
• Medium effects on pion production in heavy ion collisions
• Progress of Quantum Molecular Dynamics model and its applications in Heavy Ion Collisions
• Equation of state of dense matter in the multimessenger era
• Thermal properties of asymmetric nuclear matter with an improved isospin- and momentum-dependent interaction
• Equation of state of the neutron star matter, and the nuclear symmetry energy
• Interplay between ω-Nucleon Interaction and Nucleon Mass in Dense Baryonic Matter
• Constraining the high-density nuclear symmetry energy with the transverse-momentum dependent elliptic flow
• Analytical relations between nuclear symmetry energy and single-nucleon potentials in isospin asymmetric nuclear matter
• Transverse emission of isospin ratios as a probe of high-density symmetry energy in isotopic nuclear reactions
• Sensitivity of the neutron star r-mode instability window to the density dependence of the nuclear symmetry energy
• Probing isospin- and momentum-dependent nuclear effective interactions in neutron-rich matter
• Effective mass splitting of neutron and proton and isospin emission in heavy-ion collisions
• Energy dependence of pion in-medium effects on π^-/π^+ ratio in heavy-ion collisions
• Constraining the density dependence of the symmetry energy using the multiplicity and average $p_T$ ratios of charged pions
• Impact of NICER's Radius Measurement of PSR J0740+6620 on Nuclear Symmetry Energy at Suprasaturation Densities
• Role of the symmetry energy and the neutron-matter stiffness on the tidal deformability of a neutron star with unified equations of state
• Impact of the equation-of-state -- gravity degeneracy on constraining the nuclear symmetry energy from astrophysical observables
• Probing nuclear symmetry energy at high densities using pion, kaon, eta and photon productions in heavy-ion collisions
• Triton-${}^3$He relative and differential flows as probes of the nuclear symmetry energy at supra-saturation densities
• Pion Production in Rare Isotope Collisions
• A systematic study of the ${\pi }^{-}/{\pi }^{+}$ ratio in heavy-ion collisions with the same neutron/proton ratio but different masses
• Kinetic approach of light-nuclei production in intermediate-energy heavy-ion collisions
• Isospin-dependent pion in-medium effects on charged pion ratio in heavy ion collisions
• Nuclear fourth-order symmetry energy and its effects on neutron star properties in the relativistic Hartree-Fock theory
• Probing the high-density behavior of symmetry energy with gravitational waves
• An improved single particle potential for transport model simulations of nuclear reactions induced by rare isotope beams
• Constraints on the Neutron Skin and the Symmetry Energy from the Anti-analog Giant Dipole Resonance in 208Pb
• Insights on pion production mechanism and symmetry energy at high density
• Influence of neutron-skin thickness on ${\pi }^{-}/{\pi }^{+}$ ratio in Pb+Pb collisions
• Symmetry potential of $\Delta (1232)$ resonance and its effects on the ${\pi }^{-}/{\pi }^{+}$ ratio in heavy-ion collisions near the pion production threshold
• Nuclear symmetry energy: An experimental overview
• Symmetry energy systematics and its high density behavior
• Ruling out the supersoft high-density symmetry energy from the discovery of PSR J0740+6620 with mass $2.14_{-0.09}^{+0.10}{M}_{\odot }$
• In-medium and isospin effects on particle production near threshold energies in heavy-ion collisions
• Imprints of the nuclear symmetry energy on gravitational waves from the axial w-modes of neutron stars
• Normal or abnormal isospin-fractionation as a qualitative probe of nuclear symmetry energy at supradensities
• Modeling pion production in heavy-ion collisions at intermediate energies
• Cross-checking the symmetry energy at high densities
• Flow probe of symmetry energy in relativistic heavy-ion reactions
• Lorentz covariant nucleon self-energy decomposition of the nuclear symmetry energy
• Effects of pion potential and nuclear symmetry energy on the ${\pi }^{-}/{\pi }^{+}$ ratio in heavy-ion collisions at beam energies around the pion production threshold
• Isospin dependent properties of asymmetric nuclear matter
• Extended Skyrme interactions for transport model simulations of heavy-ion collisions
• Probing high-density nuclear symmetry energy with ${\Xi }^{-}/{\Xi }^0$ ratio in heavy-ion collisions at $\sqrt{s_{NN}}\sim 3$ GeV
• The isospin dependent nucleon-nucleon inelastic cross section in the nuclear medium
• Effect of splitting of the neutron and proton effective mass on nuclear symmetry energy at finite temperature
• Sensitivity of neutron to proton ratio toward the high density behavior of symmetry energy in heavy-ion collisions
• Efficacy of crustal superfluid neutrons in pulsar glitch models
• Neutron star cooling - a challenge to the nuclear mean field
• Effects of energy conservation on equilibrium properties of hot asymmetric nuclear matter
• Dynamics of pion production in heavy-ion collisions around 1A GeV energies
• Effects of a weakly interacting light U boson on the nuclear equation of state and properties of neutron stars in relativistic models
• Folding model study of the charge-exchange scattering to the isobaric analog state and implication for the nuclear symmetry energy
• Probing the nuclear equation of state in heavy-ion collisions at Fermi energy in isospin-sensitive exclusive experiments
• Delineating effects of tensor force on the density dependence of nuclear symmetry energy
• Pion Production in Heavy-ion Collisions in the 1 A GeV region
• Effects of nuclear symmetry energy on eta meson production and its rare decay to the dark U-boson in heavy-ion reactions
• Symmetry energy extracted from the S$\pi$RIT pion data in Sn+Sn systems
• Understanding the symmetry energy using data from the ALADIN-2000 Collaboration taken at the GSI Large Neutron Detector
• The influence of the symmetry energy on the cone-azimuthal emission
• Revisiting the Equation of State of Hybrid Stars in the Dyson-Schwinger Equation Approach to QCD
• Nuclear collective dynamics in the lattice Hamiltonian Vlasov method
• Effect of the momentum dependence of nuclear symmetry potential on pion-/pion+ ratio in heavy-ion collisions
• Model dependence of isospin sensitive observables at high densities
• A phenomenological equation of state for isospin asymmetric nuclear matter
• Effect of the momentum dependence of nuclear symmetry potential on the transverse and elliptic flows
• Heavy-ion Collisions: Direct and indirect probes of the density and temperature dependence of Esym
• Isospin Effects on Strangeness in Heavy-Ion Collisions
• Imprints of Nuclear Symmetry Energy on Properties of Neutron Stars
• Symmetry energy and neutron star properties in the saturated Nambu-Jona-Lasinio model
• Studies of the equation-of-state of nuclear matter by heavy-ion collisions at intermediate energy in the multi-messenger era
• Isobaric incompressibility of the isospin asymmetric nuclear matter
• Collective flows of pions in Au+Au collisions at energies 1.0 and 1.5 GeV/nucleon
• Nuclear Symmetry Energy from QCD sum rules
• Influence of differential elastic nucleon-nucleon cross section on stopping and collective flows in heavy-ion collisions at intermediate energies
• Nuclear fragmentation and charge-exchange reactions induced by pions in the $\Delta$-resonance region
• Nuclear collective dynamics in transport model with the lattice Hamiltonian method
• Probing Nuclear Symmetry Energy and its Imprints on Properties of Nuclei, Nuclear Reactions, Neutron Stars and Gravitational Waves
• Gravitational waves from isolated neutron stars: mass dependence of r-mode instability
• Impact parameter smearing effects on isospin sensitive observables in heavy ion collisions
• Effect of the $\sigma$-cut potential on the properties of neutron stars with or without a hyperonic core
• Effects of Pauli blocking on pion production in central collisions of neutron-rich nuclei
• Effect of energy conservation on in-medium $\mbox{NN}\to \mbox{N}Δ$ cross section in isospin-asymmetric nuclear matter
• Observing the Ping-pong Modality of Isospin Degree of Freedom in Cluster Emission from Heavy Ion Reactions
• Effects of symmetry energy in ${}^{132}\mathrm{Sn}{+}^{124}\mathrm{Sn}$ reaction at 300 MeV/nucleon
• Effects of the high-momentum tail of nucleon momentum distribution on the isospin-sensitive observables
• The effect of internal magnetic field on collective flow in heavy ion collisions at intermediate energies
• Relationship between the symmetry energy and the single-nucleon potential in isospin-asymmetric nucleonic matter
• Effects of nuclear symmetry energy and in-medium NN cross section in heavy-ion collisions at beam energies below the pion production threshold
• Effects of the U-boson on the inner edge of neutron star crusts
• Competition between Coulomb and Symmetry Potential in Semi-peripheral Heavy-ion Collisions
• Hyperon and nuclear symmetry energy in the neutron star
• Low-momentum interactions with Brown-Rho-Ericson scalings and the density dependence of the nuclear symmetry energy
• The symmetry energy in nuclear reactions
• The effect of Lorentz-like force on collective flows of K${}^{+}$ in Au+Au collisions at 1.5 GeV/nucleon}{The effect of Lorentz-like force on collective flows of $K^{+}$ in Au+Au collisions at 1.5 GeV/nucleon
• Core-crust transition and crustal fraction of moment of inertia in neutron stars
• Examination of an isospin-dependent single-nucleon momentum distribution for the isospin-asymmetric nuclear matter in heavy-ion collisions
• The density- and isospin- dependent $\Delta$-formation cross section and its decay width
• From finite nuclei to neutron stars : the essential role of high-order density dependence in effective forces
• The ASY-EOS experiment at GSI: investigating the symmetry energy at supra-saturation densities
• Effects of retarded electrical fields on observables sensitive to the high-density behavior of nuclear symmetry energy in heavy-ion collisions at intermediate energies
• Auxiliary Function Approach for Determining Symmetry Energy at Supra-saturation Densities
• Symmetry coefficients and incompressibility of clusterized supernova matter
• Specific viscosity of neutron-rich nuclear matter from a relaxation time approach
• Introduction to low-momentum effective interactions with Brown-Rho scaling and three-nucleon forces
• Role of dense matter in tidal deformations of inspiralling neutron stars and in gravitational waveform with unified equations of state
• Influence of density dependent symmetry energy on Elliptical flow
• From nuclear reactions to compact stars: a unified approach
• Global analysis of Skyrme forces with higher-order density dependence
• Nuclear symmetry energy and proton-rich reactions at intermediate energies
• Accreting neutron stars from the nuclear energy-density functional theory. II. Equation of state and global properties
• Isospin asymmetric nuclear matter and properties of axisymmetric neutron stars
• Flavor Symmetry and Topology Change in Nuclear Symmetry Energy for Compact Stars
• Beam energy dependence of the relativistic retardation effects of electrical fields on the ${\pi }^{-}/{\pi }^{+}$ ratio in heavy-ion collisions
• Probing the momentum-dependence of the symmetry potential by the free n/p ratio of preequilibrium emission
• Equation of state and hybrid star properties with the weakly interacting light U-boson in relativistic models
• Initialization effects of nucleon profile on the $\pi$ yields in heavy-ion collisions at medium energies
• Toward an Effective Field Theory for Cold Compressed Baryonic Matter
• High Density with Elliptic Flows
• Initialization effect in heavy-ion collisions at intermediate energies
• One possible mechanism for massive neutron star supported by soft EOS
• Symmetry energy softening in nuclear matter with non-nucleonic constituents
• Probing nuclear symmetry energy with the sub-threshold pion production
• Isovector channel of quark-meson-coupling model and its effect on symmetry energy
• Can the nuclear symmetry potential at supra-saturation densities be negative?
• Symmetry energy of super-dense neutron-rich matter from integrating barotropic pressures in neutron stars and heavy-ion reactions
• Disentangling effects of collision geometry and symmetry energy in U+U collisions
• A new probe to study symmetry energy at low density by deuteron breakup reaction
• Effects of medium-induced $\rho -\omega$ meson mixing on the equation of state in isospin-asymmetric nuclear matter
• Experimental nuclear astrophysics in Italy
• Symmetry Energy from Holographic QCD
• Probing into the Possible Range of the U Bosonic Coupling Constants in Neutron Stars Containing Hyperons
• Nucleon Short-Range Correlations and High-Momentum Dynamics: Implications on the Equation of State of Dense Matter
• Pion production and absorption in heavy-ion collisions
• Revisit to the yield ratio of triton and ${}^3$He as an indicator of neutron-rich neck emission
• Blind spots of probing the high-density symmetry energy in heavy-ion collisions
• Sensitivity of deexcitation energies of superdeformed secondary minima to the density dependence of symmetry energy with the relativistic mean-field theory
• Necessity of selfconsistent calculations for the electromagnetic field in probing the nuclear symmetry energy using pion observables in heavy-ion collisions
• Nuclear collision in strong magnetic field
• Symmetry Energy and Universality classes of holographic QCD
• Probing the hadron-quark mixed phase at high isospin and baryon density - Sensitive observables
• Elimination of influence of neutron-skin size difference of initial colliding nuclei in Pb+Pb collisions
• Probing in-medium nucleon-nucleon inelastic scattering cross section by using energetic n/p ratio
• Constraining the Hadron-Quark Phase Transition Chemical Potential via Astronomical Observation
• Correlation between nuclear temperatures and symmetry energy in sub-saturation
• Three-body Force Effects on the Properties of Neutron-rich Nuclear Matter
• Effects of an induced electric field on π^{-}/π^{+} ratio in heavy-ion collisions
• Probing the symmetry energy at high baryon density with heavy ion collisions
• In-medium $\Delta (1232)$ potential, pion production in heavy-ion collisions and the symmetry energy
• Nucleon-$\Delta$ elastic cross section in isospin-asymmetric nuclear medium with inclusion of scalar-isovector $\delta$ meson field
• Effects of Symmetry Energy in the Reaction 40Ca+124Sn at 140 MeV/nucleon
• Ground-state properties of light kaonic nuclei signaling symmetry energy at high densities
• Origins and Impacts of High-Density Symmetry Energy
• Effective interaction: From nuclear reactions to neutron stars
• Neutron Star Equation of State with Nucleon Short-Range Correlations: A Concise Review and Open Issues
• Basic quantities of the Equation of State in isospin asymmetric nuclear matter
• In-medium effects of nucleon-nucleon cross sections in heavy-ion collisions
• Angular momentum conservation and pion production in intermediate-energy heavy-ion collisions
• Probing the density dependence of symmetry energy at subsaturation density with HICs
• In-medium pion dispersion relation and medium correction of $N\pi \leftrightarrow \Delta$ near the threshold energy of pion production