Yield ratios and directed flows of light particles from proton-rich nuclei-induced collisions

The neutron-to-proton and ^3H -to- ^3He yield ratios, and the directed flows of particles dependent on a reduced rapidity, the transverse momentum per nucleon, and a reduced impact parameter are investigated for ^28S + ^28Si and ^32S + ^28Si systems at 50 and 400 MeV/u using an isospin-dependent quantum molecular dynamics model. The results show that these yield ratios of projectile-like fragments are approximately equal to the constituent neutron-to-proton ratio of the projectile. There are clear differences of the directed flows for isospin-related fragments neutron and proton, ^3H and ^3He from ^28S + ^28Si collisions. The differences in directed flows for neutrons and protons and ^3H – ^3He from a proton-rich nucleus ^28S- induced collisions are noticeably larger than those from a stable nucleus ^32S- induced reactions under medium impact parameters. Thus, the yield ratios and differences in directed flows for the neutrons and protons and ^3H – ^3He under medium impact parameters are proposed as possible observable items for studying isospin physics.