Rapidity distribution of protons from the potential version of UrQMD model and the traditional coalescence afterburner

Abstract

Rapidity distributions of both E895 proton data at AGS energies and NA49 net proton data at SPS energies can be described reasonably well with a potential version of the UrQMD in which mean-field potentials for both pre-formed hadrons and confined baryons are considered, with the help of a traditional coalescence afterburner in which one parameter set for both relative distance $R_0$ and relative momentum $P_0$, (3.8 fm, 0.3 GeV$/$c), is used. Because of the large cancellation between the expansion in $R_0$ and the shrinkage in $P_0$ through the Lorentz transformation, the relativistic effect in clusters has little effect on the rapidity distribution of free (net) protons. Using a Woods-Saxon-like function instead of a pure logarithmic function as seen by FOPI collaboration at SIS energies, one can fit well both the data at SIS energies and the UrQMD calculation results at AGS and SPS energies. Further, it is found that for central Au+Au or Pb+Pb collisions at top SIS, SPS and RHIC energies, the proton fractions in clusters are about 33$\%$, 10$\%$, and 0.7$\%$, respectively.

9 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1507.06033

References in corpus (6)

• Systematics of central heavy ion collisions in the 1A GeV regime
• Directed flow, a signal for the phase transition in Relativistic Nuclear Collisions?
• The effect of "pre-formed" hadron potentials on the dynamics of heavy ion collisions and the HBT puzzle
• Effects of a phase transition on HBT correlations in an integrated Boltzmann+Hydrodynamics approach
• Scaling of $v_2$ in heavy ion collisions
• Transport model study of nuclear stopping in heavy ion collisions over an energy range from 0.09A GeV to 160A GeV

Cited by in corpus (13)

• Particle production and equilibrium properties within a new hadron transport approach for heavy-ion collisions
• Light Nuclei Production in Au+Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5-200 GeV from JAM model
• Light nuclei production in relativistic heavy ion collisions from the AMPT model
• Effects of in-medium nucleon-nucleon cross section on collective flow and nuclear stopping in heavy-ion collisions in the Fermi-energy domain
• Light nuclei production in Au + Au collisions at $\sqrt{s_{NN}}$ = 7.7-80 GeV from UrQMD model
• Effects of sequential decay on collective flows and nuclear stopping power in heavy-ion collisions at intermediate energies
• The effect of internal magnetic field on collective flow in heavy ion collisions at intermediate energies
• Proton correlations and apparent intermittency in the UrQMD model with hadronic potentials
• 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
• Helium-3 production from Pb+Pb collisions at SPS energies with the UrQMD model and the traditional coalescence afterburner
• The cumulants of the baryon number from central Au+Au collision at $E_{lab}$= 1.23 GeV$/$nucleon reveal the nuclear mean-field potentials
• Nuclear interactions and net-proton number fluctuations in heavy ion collisions at the SIS18 accelerator
• 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