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Within the framework of quantum molecular dynamics transport model, the isospin and in-medium effects on the hyperon production in the reaction of 197 Au + 197 Au are investigated thoroughly. A repulsive hyperon-nucleon potential from the chiral effective field theory is implemented into the model, which is related to the hyperon momentum and baryon density. The correction on threshold energy of the elementary hyperon cross section is taken into account. It is found that the 𝛴 yields are suppressed in the domain of midrapidity and kinetic energy spectra with the potential. The hyperons are emitted in the reaction plane because of the strangeness exchange reaction and reabsorption process in the nuclear medium. The 𝛴 − /𝛴 + ratio depends on the stiffness of nuclear symmetry energy, in particular in the high-energy region (above 500 MeV).

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The dynamics of high-energy proton-induced spallation reactions on target nuclides of 56Fe, 58Ni, 107Ag, 112Cd, 184W, 181Ta, 197Au, and 208Pb are investigated with the quantum molecular dynamics transport model motivated by the China initiative Accelerator Driven System (CiADS) in Huizhou and the China Spallation Neutron Source (CSNS) in Dongguan. The production mechanism of light nuclides and fission fragments is thoroughly analyzed, and the results obtained thereby are compared with available experimental data. The statistical code GEMINI is employed in conjunction with a transport model for describing the decay of primary fragments. For the treatment of cluster emission during the preequilibrium stage, a surface coalescence model is implemented into the model. It is found that the available data in terms of total fragment yields are well reproduced in the combined approach for spallation reactions both on the heavy and light targets. The energetic light nuclides (deuteron, triton, helium isotopes etc) mainly created during the preequilibrium stage are treated within the framework of surface coalescence, whereas their evaporation is described in the conventional manner by the GEMINI code. With this combined approach, a good overall description of light clusters and neutron emission is obtained, and some discrepancies with the experimental data are discussed. Possible production of radioactive isotopes in the spallation reactions is also analyzed, i.e., the 6,8He energy spectra.

Within the framework of the quantum molecular dynamics transport model, the pion production and isospin effect in heavy-ion collisions have been thoroughly investigated. The energy conservation in the decay of ∆ and reabsorption of pion in nuclear medium are taken into account. The influence of the stiffness of symmetry energy and the pion potential on the pion production are systematically investigated and compared with the FOPI data via the transverse momentum, longitudinal rapidity and collective flow in collisions of 197 Au + 197 Au. It is manifested that the pion yields are slightly suppressed in the domain of mid-rapidity and high momentum. The antiflow phenomena is reduced by implementing the pion potential and more consistent with the experimental data. The isospin diffusion in the high-density region (1.2ρ0 -1.8ρ0) is investigated by analyzing the neutron/proton and π − /π + ratios in the reaction of 132 Sn + 124 Sn at the incident energy of 270 MeV/nucleon. A soft symmetry energy with the slope parameter of L(ρ0) = 42 ± 25 MeV is obtained by analyzing the experimental data from the SπRIT collaboration.