Constraining the high-density nuclear symmetry energy with the transverse-momentum dependent elliptic flow

Abstract

Within the newly updated version of the ultrarelativistic quantum molecular dynamics (UrQMD) model, the transverse-velocity dependence of the elliptic flow of free nucleons from ${}^{197}$Au+${}^{197}$Au collisions at the incident energy 400 MeV$/$nucleon is studied within different windows of the normalized c.m. rapidity $y_0$. It is found that the elliptic flow difference $v_2^n$-$v_2^p$ and ratio $v_2^n$/$v_2^p$ of neutrons versus protons are sensitive to the density dependence of the symmetry energy, especially the ratio $v_2^n$/$v_2^p$ at small transverse velocity in the intermediate rapidity intervals $0.4<|y_0|<0.6$. By comparing either transverse-momentum dependent or integrated FOPI/LAND elliptic flow data of nucleons and hydrogen isotopes with calculations using various Skyrme interactions, all exhibiting similar values of isoscalar incompressibility but very different density dependences of the symmetry energy, a moderately soft to linear symmetry energy is extracted, in good agreement with previous UrQMD or Tübingen QMD model calculations but contrasting results obtained with ${\pi }^{-}/{\pi }^{+}$ yield ratios available in the literature.

20 pages, 6 figures, accepted by Phys. Rev. C

References in corpus (17)

• Nuclear symmetry energy probed by neutron skin thickness of nuclei
• Constraints on the symmetry energy and on neutron skins from the pygmy resonances in 68Ni and 132Sn
• Symmetry Energy I: Semi-Infinite Matter
• The Giant Dipole Resonance as a quantitative constraint on the symmetry energy
• Symmetry energy from elliptic flow in 197Au + 197Au
• Systematics of central heavy ion collisions in the 1A GeV regime
• Giant Quadrupole Resonances in 208Pb, the nuclear symmetry energy and the neutron skin thickness
• Elliptic flow and system size dependence of transition energies at intermediate energies
• Analysis of bulk and surface contributions in the neutron skin of nuclei
• Nuclear symmetry energy at subnormal densities from measured nuclear masses
• Nuclear matter symmetry energy and the symmetry energy coefficient in the mass formula
• Isospin effects in the disappearance of flow as a function of colliding geometry
• Density dependence of nuclear symmetry energy constrained by mean-field calculations
• Origin of symmetry energy in finite nuclei and density dependence of nuclear matter symmetry energy from measured alpha-decay energies
• Isospin dependence of relative yields of $K^{+}$ and $K^0$ mesons at 1.528 AGeV
• UrQMD calculations of two-pion HBT correlations in central Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV
• Effect of the momentum dependence of nuclear symmetry potential on pion-/pion+ ratio in heavy-ion collisions

Cited by in corpus (11)

• Results of the ASY-EOS experiment at GSI: The symmetry energy at suprasaturation density
• Progress of Quantum Molecular Dynamics model and its applications in Heavy Ion Collisions
• Normal or abnormal isospin-fractionation as a qualitative probe of nuclear symmetry energy at supradensities
• ${}^3$H/${}^3$He ratio as a probe of the nuclear symmetry energy at sub-saturation densities
• Influence of differential elastic nucleon-nucleon cross section on stopping and collective flows in heavy-ion collisions at intermediate energies
• The effect of internal magnetic field on collective flow in heavy ion collisions at intermediate energies
• Competition between Coulomb and Symmetry Potential in Semi-peripheral Heavy-ion Collisions
• Symmetry energy at subsaturation densities and the neutron skin thickness of 208Pb
• Effect of the spin-orbit interaction on flows in heavy-ion collisions at intermediate energies
• A new probe to study symmetry energy at low density by deuteron breakup reaction
• Beam energy dependence of cumulants of the net-baryon, net-charge and deuteron multiplicity distributions in Au+Au collisions at $\sqrt{s_{NN}}=3.0-5.0$ GeV