Study of the out-of-plane emission of protons and light fragments in symmetric heavy-ion collisions

Midrapidity protons from 209Bi+209Bi collisions were measured with the Kaon Spectrometer at SIS at incident energies of ELab/A=400, 700 and 1000 MeV. Additionally, light fragments were analysed at 400 MeV. We have investigated the azimuthal emission pattern of the particles relative to the reaction plane as function of transverse momentum, bombarding energy and impact parameter. We observe an enhanced emission of particles perpendicular to the reaction plane at all bombarding energies. The ratio of the number of particles emitted out-of-plane/in-plane increases strongly with the particles transverse momentum. The anisotropy decreases with increasing beam energy. Composite particles show a much stronger effect than protons. (orig.)