Absorption mechanisms in photon induced two-body knockout
arXiv:nucl-th/9307002 · doi:10.1016/0370-2693(93)90650-7
Abstract
Calculations have been performed for the $^{16}$O($γ$,pn) and the $^{16}$O($γ$,pp) reaction in the photon-energy range $E_γ$ = 60-300 MeV. Besides the contribution from the more common photoabsorption on the pionic degrees of freedom, we have investigated the influence of heavier meson exchange ($Ï, Ï, Ï$) and intermediate $Î$ creation with $Ï$ and $Ï$ exchange. Whereas the $Ï$ meson is found to set the main trends, the $Ï$ meson is found not to be discardable in a theoretical description of the ($γ$,pn) reaction. The incorporation of an energy dependence and a decay width in the $Î$ propagator is observed to be essential in order to arrive at a more realistic description of ($γ$,NN) reactions at higher photon energies.
10 pages, 5 figures in seperate postscript file, Submitted to Phys. Lett. B. - INW9306II