Pion Productions with Isospin-Dependent In-Medium Cross Sections

Total pion yields and π−/π+ ratios in two Sn+Sn collision systems, 132Sn+124Sn (neutron rich) and 108Sn+112Sn (neutron poor) at E=270A MeV, are significant observables in SAMURAI Pion-Reconstruction and Ion-Tracker (SπRIT) experiments. Based on a recently developed transport model, DaeJeon Boltzmann–Uehling–Uhlenbeck (DJBUU), we investigate the isospin-dependent inmedium effects by including density- and isospin-dependent cross sections for Δ baryon productions. We compare our results with the SπRIT data by considering these effects. We find that the yields as well as the ratios strongly depend on the in-medium effect, especially isospin-dependent in-medium cross sections for Δ resonances.