Diabaticity in heavy-ion collisions and its role in non-equilibrium neutron emission

Slow collective nuclear motions such as heavy-ion collision slightly above the Coulomb barrier and induced nuclear fission imply collective velocities. In the vicinity of quasi-crossings of adiabatic levels the nuclear single-particle motion changes completely. A nucleon in the lower level before the crossing will find itself in the upper level if this has been unoccupied before and the nucleon will stay in the diabatic level. The diabatic potential now corresponds to the extra energy pumped into the system due to the diabatic production of particle-hole state. An interesting aspect of diabatic s.p. states is their connection with non-equilibrium neutron or proton emission in heavy-ion collisions. Several neutrons could be emitted of the s.p. states to the collective motion which produces highly excited s.p. states