On a semimicroscopic description of extremely simple photonuclear reactions involving the excitation of a giant dipole resonance

Direct-decay properties of giant resonances

“…[8]. Following this procedure the partial neutron-radiative-capture cross sections for 89 Y, 140 Ce, and 208 Pb target-nuclei have satisfactorily been described without the use of new parameters [9]. Actually, the present model can be regarded as the semi-microscopic version of the well-known phenomenological DSD-model (see, e.g., Ref.…”

“…[8] from the semi-microscopic description of the total width of a few isoscalar resonances in a number of singly-and doubly-closed shell nuclei. In the description of the isovector GRs we occasionally change the strength of spreading parameter by a small amount to improve the description of the experimental strength distribution [9]. It should be stressed, that after the above-outlined choice of the model parameters we do not use any new parameters to describe the direct-nucleon-decay properties of a given GR.…”

“…We also take into account, in an effective way, the (relatively small) contribution of isovector momentumdependent forces in formation of the isovector GRs by using a scaling transformation of the reaction amplitudes calculated within the CRPA. The corresponding strength parameter k L (the "velocity" parameter), which describes the contribution of the momentum-dependent forces in the corresponding energy-weighted sum rule, is taken such that description of the peak energy (and exhaustion of the total strength) for given isovector GR is improved [9][10][11][12][13].…”

“…In this work we briefly describe the approach and present recent results concerned with semi-microscopic description of direct-decay properties of a few isovector giant resonances [9][10][11][12][13].…”

Description of the simplest photonuclear reactions within the particle-hole dispersive optical model

“…The cross section σ μ,E1 (ω) determines the partial probability b μ,E1 (δ) for direct neutron decay of the IVGDR with the population of μ −1 single-hole state of the product-nucleus in accordance with the relation [7,10,17] …”