Energy and Target Dependence of Azimuthal Distributions atMid-Rapidity in Mediate-Energy Nuclear Reactions

The azimuthal distributions at mid-rapidity for ⁴⁰Ar-induced reactions are investigated by nuclear transport theory. The rotation-like behavior which is one of collective motions becomes stronger with the increasing of the impact parameter and weaker with the increasing of the projectile energy. At about 85 MeV/nucleon the rotation-like behavior almost vanishes for ⁴⁰Ar + ²⁷Al system. While the rotation-like behavior becomes weaker and the out-of-plane enhancement of particle emission is revealed with the increasing of target mass. Some quantitative agreements with the experiment data are also obtained.