The structure of the Gamow Teller giant resonance and interpretation of beta-delayed neutron spectra

It is shown that the selective population of states in the neutron- emitter in beta -delayed neutron emission observed recently can be explained by a structure of the Gamow-Teller giant resonance not included in the 'gross theory' of beta -decay. Extrapolating the information on this structure available from the isovector M1 gamma - decay of isobaric analogue states in nuclei in the valley of beta - stability to neutron-rich nuclei can account qualitatively for the observed selectivity.