Photodisintegration ofBe9

The reaction ${\mathrm{Be}}^9(\gamma , n){\mathrm{Be}}^8$ is discussed for those transitions in which the odd neutron goes from an initial $p$ state, assumed to be strongly coupled to a deformed ${\mathrm{Be}}^8$ core, to an $s$ state in the continuum. The relation between this strong-coupling model and the single-nucleon calculations of Francis, Goldman, and Guth is given. The model is applied to experiments recently reported by Jakobson, and accounts for the observed increase in cross section observed at an excitation energy of 4.6 Mev, the isotropic distribution of the neutrons associated with this rise, and the ratio of the integrated cross section for this rise to that for the threshold peak.