Modeling pion production in heavy-ion collisions at intermediate energies

Abstract

Pion production in nucleus-nucleus collisions at intermediate energies was modeled in the framework of the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model. The effects of nucleon-nucleon short-range correlations in initialization and mean-field potential, isospin-dependent in-medium baryon-baryon elastic and inelastic cross sections, and pion in-medium effect are all considered in this model. It is found that the ratio and yields of ${\ensuremath{\pi}}^{\ensuremath{-}}\mathrm{and}\phantom{\rule{4.pt}{0ex}}{\ensuremath{\pi}}^{+}$ in Au + Au reaction at 400 MeV/nucleon reproduce the FOPI data at GSI very well especially with a soft symmetry energy in the present transport model. Predictions on the single and double ${\ensuremath{\pi}}^{\ensuremath{-}}/{\ensuremath{\pi}}^{+}$ ratio are made for the isotope reaction systems $^{132}\mathrm{Sn}+^{124}\mathrm{Sn}$ and $^{108}\mathrm{Sn}+^{112}\mathrm{Sn}$ at 300 MeV/nucleon since related experiments are being carried out at RIKEN in Japan.