Probing neutron-skin thickness with free spectator neutrons in ultracentral high-energy isobaric collisions

Abstract

We show that the yield ratio of free spectator neutrons produced in high-energy ${}^{96}$Zr+${}^{96}$Zr to ${}^{96}$Ru+${}^{96}$Ru collisions is a clean probe of the neutron-skin thickness of colliding nuclei and the slope parameter $L$ of the symmetry energy. The idea is demonstrated based on the proton and neutron density distributions via a state-of-the-art Skyrme-Hartree-Fock-Bogolyubov calculation. Among spectator nucleons given by the Glauber model, free spectator neutrons include those from direct production that survive from clusterization as well as those from deexcitation of heavy clusters described by the popular GEMINI model. More free neutrons are produced in collisions of ${}^{96}$Zr nucleus due to its larger neutron skin, compared to those produced in collisions of ${}^{96}$Ru nucleus with a smaller neutron skin. The difference of the free spectator neutron yield is further increased with the increasing difference of the neutron-skin thickness between ${}^{96}$Zr and ${}^{96}$Ru with a larger $L$ value, and the increase in ultracentral collisions is particularly insensitive to model details and experimental uncertainties. Since the production of free spectator neutrons is not affected by the complicated dynamics in the mid-rapidity region, the ratio of their multiplicities in ultracentral isobaric collisions is a robust observable for constraining the neutron skin and $L$ value.

arXiv comment6 pages, 4 figures

References in corpus (34)

• Nuclear ground-state masses and deformations: FRDM(2012)
• Neutron Star Observations: Prognosis for Equation of State Constraints
• Recent Progress and New Challenges in Isospin Physics with Heavy-Ion Reactions
• Neutron-Rich Nuclei in Heaven and Earth
• Accurate Determination of the Neutron Skin Thickness of ${}^{208}$Pb through Parity-Violation in Electron Scattering
• Surface diffuseness correction in global mass formula
• Nuclear symmetry energy probed by neutron skin thickness of nuclei
• Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering
• Implications of PREX-II on the equation of state of neutron-rich matter
• Neutron Radii in Mean-Field Models
• Density slope of the nuclear symmetry energy from the neutron skin thickness of heavy nuclei
• Centrality Dependence of Charged Particle Multiplicity in Au-Au Collisions at sqrt(s_NN)=130 GeV
• Equation of state of asymmetric nuclear matter and collisions of neutron-rich nuclei
• A systematic description of evaporation spectra for light and heavy compound nuclei
• Neutron skin of ${}^{208}$Pb from Coherent Pion Photoproduction
• Axially deformed solution of the Skyrme-Hartree-Fock-Bogolyubov equations using the transformed harmonic oscillator basis (II) HFBTHO v2.00d: a new version of the program
• Constraining the symmetry energy at subsaturation densities using isotope binding energy difference and neutron skin thickness
• Neutron density distributions from antiprotonic 208Pb and 209Bi atoms
• Light cluster production in intermediate energy heavy-ion collisions induced by neutron-rich nuclei
• Neutron skins of atomic nuclei: per aspera ad astra
• Light nuclei quasiparticle energy shift in hot and dense nuclear matter
• Proton elastic scattering from tin isotopes at 295 MeV and systematic change of neutron density distributions
• Parameterization of Deformed Nuclei for Glauber Modeling in Relativistic Heavy Ion Collisions
• Probing triaxial deformation of atomic nuclei in high-energy heavy ion collisions
• Evidence of the triaxial structure of ${}^{129}$Xe at the Large Hadron Collider
• Probing the neutron skin with ultrarelativistic isobaric collisions
• Implications of PREX-2 on the electric dipole polarizability of neutron rich nuclei
• Neutron skins of ${}^{208}$Pb and ${}^{48}$Ca from pionic probes
• Bayesian inference of nuclear symmetry energy from measured and imagined neutron skin thickness in ${}^{116,118,120,122,124,130,132}$Sn, ${}^{208}$Pb, and ${}^{48}$Ca
• Probing nuclear quadrupole deformation from correlation of elliptic flow and transverse momentum in heavy ion collisions
• Analytical coalescence formula for particle production in relativistic heavy-ion collisions
• Beam Energy dependence of Light Nuclei Production in Au+Au Collisions
• A Centrality Detector Concept
• Incorporating the weak mixing angle dependence to reconcile the neutron skin measurement on 208Pb by PREX-II

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