Collective flow of light particles in Au + Au collisions at intermediate energies

The Skyrme potential energy density functional is introduced into the ultrarelativistic quantum molecular dynamics model and the updated version is applied to studying the directed and elliptic flows of light particles (protons, neutrons, deuterons, tritons, ³He, and ⁴He) in ¹⁹⁷Au + ¹⁹⁷Au collisions at beam energies 150, 250, and 400 MeV/nucleon. The results are compared with the recent FOPI experimental data. It is found that the yields and collective flows of light particles can be described quite well. The influence of the equation of state, medium-modified nucleon-nucleon elastic cross sections (NNECS) and cluster recognition criteria on the directed and elliptic flows is studied in detail. It is found that the flows of light particles are sensitive to the medium-modified NNECS, but not sensitive to the isospin dependent cluster recognition criteria. It seems difficult, however, even with the new data and calculations, to obtain a more accurate constraint on the nuclear incompressibility K₀ than the interval 200-260 MeV.