Antiproton production from high energy heavy-ion collisions

Based on the fireball model, we find that the secondary process ρρ → panti p involving the ρ meson produced from the reaction contributes significantly to the production of antiprotons from heavy-ion collisions at subthreshold energies. Using the kinetic model, we have calculated the ratio of the antiproton number to the pion number in high-energy heavy-ion collisions. At an incident energy of 2.1 GeV/nucleon available at Bevalac, this ratio is found to be ≅ 1.1x10-7, which has a similar magnitude as that of the preliminary data. (orig.)