The Landau-Zener effect in nuclear molecules

In atomic molecules the atoms share their valence electrons. Similarly, in a nucleus-nucleus collision nuclear molecules are formed when the outermost bound nucleons move in molecular orbits. Unique signatures of the formation of molecular orbits and consequently of nuclear molecules arise in those reaction channels which involve enhanced nucleon promotion due to the avoided crossing of molecular single nucleon levels ('nuclear Landau-Zener effect'). The author reviews the present status of the investigation of the nuclear Landau-Zener effect in light heavy ion reactions within the framework of the molecular particle-core approach. Semiclassical treatments and the molecular particle-core model, which is a quantum mechanical molecular reaction theory describing valence nucleon orbits by eigenstates of the two-centre shell model, give cross sections with specific signatures of the Landau-Zener effect. Dynamic reaction calculations within the molecular particle-core model for the 17 O+ 12 C reaction are discussed. For heavier scattering systems molecular level diagrams are calculated with the two-centre shell model to predict enhanced transitions of nucleons.