Effects of nuclear symmetry energy and in-medium NN cross section in heavy-ion collisions at beam energies below the pion production threshold

Abstract

Based on the isospin-dependent Boltzmann-Uehling-Uhlenbeck(IBUU04) transport model, we explored effects of in-medium $NN$ elastic scattering cross section and nuclear symmetry energy on the sub-threshold pion production in ${}^{132}Sn{+}^{124}Sn$ reaction. We find that with decrease of incident beam energy, effects of in-medium $NN$ elastic scattering cross section on the ${\pi }^{-}/{\pi }^{+}$ ratio are larger than that of the symmetry energy although the latter may be also larger. While keeping the effect of symmetry energy, the double ratio of ${\pi }^{-}/{\pi }^{+}$ from neutron-rich and neutron-poor reaction systems (with the same mass number of system) ${}^{132}Sn{+}^{124}Sn$ and ${}^{128}Pm{+}^{128}Pm$ almost fully cancels out the effects of in-medium $NN$ elastic scattering cross section.

arXiv comment5 pages, 7 figures. added one figure and related discussions, accepted by PRC

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Cited by in corpus (9)

• Comparison of heavy-ion transport simulations: Collision integral with pions and $\Delta$ resonances in a box
• Dynamics of clusters and fragments in heavy-ion collisions
• The impact of energy conservation in transport models on the ${\pi }^{-}/{\pi }^{+}$ multiplicity ratio in heavy-ion collisions and the symmetry energy
• Probing neutron-proton dynamics by pions
• Symmetry energy extracted from the S$\pi$RIT pion data in Sn+Sn systems
• Effects of Pauli blocking on pion production in central collisions of neutron-rich nuclei
• Effects of symmetry energy in ${}^{132}\mathrm{Sn}{+}^{124}\mathrm{Sn}$ reaction at 300 MeV/nucleon
• Probing in-medium nucleon-nucleon inelastic scattering cross section by using energetic n/p ratio
• In-medium effects of nucleon-nucleon cross sections in heavy-ion collisions