A model comparison of resonance lifetime modifications, a soft equation of state and non-Gaussian effects on $\pi -\pi$ correlations at FAIR/AGS energies

Abstract

HBT correlations of ${\pi }^{-}-{\pi }^{-}$ pairs at FAIR/AGS energies are investigated by using the UrQMD transport model and the CRAB analyzing program. Three different possible sources (treatment of resonance lifetimes, a soft equation of state and non-Gaussian effects) to understand the HBT $R_O/R_S$ puzzle are investigated. Firstly, we find that different treatments of the resonance decay time can not resolve the HBT time-related puzzle, however it can modify the HBT radii at low transverse momenta to some extent to explain the data slightly. Secondly, with a soft equation of state with momentum dependence, the measured transverse momentum dependent HBT radii and $R_O/R_S$ ratio can be described fairly well. Thirdly, non-Gaussian effects are visible in the calculated correlation function. Using the Edgeworth expansion, one finds that the non-Gaussian effect is strongest in the longitudinal direction and weakest in the sideward direction.

18 pages, 6 figures. To be published in J.Phys. G

References in corpus (7)

• Directed and elliptic flow in heavy ion collisions from $E_{\mathrm{beam}}=90$ MeV/nucleon to $E_{c.m.}=200$ GeV/nucleon
• The effect of "pre-formed" hadron potentials on the dynamics of heavy ion collisions and the HBT puzzle
• Probing the symmetry energy and the degree of isospin equilibrium
• Transport model study of the $m_T$-scaling for $\Lambda$, K, and $\pi$ HBT-correlations
• Transport model analysis of particle correlations in relativistic heavy ion collisions at femtometer scales
• Pion freeze-out as seen through HBT correlations in heavy ion collisions from FAIR/AGS to RHIC energies
• Transport model analysis of the transverse momentum and rapidity dependence of pion interferometry at SPS energies

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• UrQMD calculations of two-pion HBT correlations in central Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV
• Transport model study of nuclear stopping in heavy ion collisions over an energy range from 0.09A GeV to 160A GeV
• Proton correlations and apparent intermittency in the UrQMD model with hadronic potentials
• Elliptic flow splitting between protons and antiprotons from hadronic potentials
• 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
• Probing the Three-dimension Emission Source and Neutron Skin via $\pi$-$\pi$ Correlations in Heavy-Ion Collisions