Semimicroscopic calculation of the 28Si nucleus photodisintegration

Spectroscopic data are used for calculation of doorway dipole states of the 28Si nucleus (the calculation is carried out in the random phase approximation) and for statistical description of decays of the doorway states into states which are more complex than the 1p1h configurations. Some individual features of 28Si photoiisintegration are explained. It is shown that the structure of the 28Si giant resonance in the energy range of 18-23 MeV is associated with the doorway states which are built on the 1p1h basis generated from the realistic ground state of the nucleus. Analyzing the relaxation process one concludes that the dipole excitation of 28Si does not produce a compound state. The 28Si nucleus does not reach the thermal equilibrium state. Therefore the emitted photoproton spectrum is essentially hard