FOPI

                     A Detector for Physics of Nuclear Reactions at Intermediate and Relativistic Energies
Transition Energy

The incident energy at which the azimuthal distributions in semi-central heavy ion collisions change from in-plane to out-of-plane enhancement - Etran was studied as a function of mass of emitted particles, their transverse momentum and centrality for Au+Au collisions.

A systematic decrease of Etran as a function of mass of the reaction products, their transverse momentum and collision centrality is evidenced.