Absorption mechanisms in photon induced two-body knockout

Abstract

Calculations have been performed for the ${}^{16}$O($\gamma$,pn) and the ${}^{16}$O($\gamma$,pp) reaction in the photon-energy range $E_{\gamma }$ = 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 ($\rho ,\sigma ,\omega$) and intermediate $\Delta$ creation with $\pi$ and $\rho$ exchange. Whereas the $\pi$ meson is found to set the main trends, the $\rho$ meson is found not to be discardable in a theoretical description of the ($\gamma$,pn) reaction. The incorporation of an energy dependence and a decay width in the $\Delta$ propagator is observed to be essential in order to arrive at a more realistic description of ($\gamma$,NN) reactions at higher photon energies.

10 pages, 5 figures in seperate postscript file, Submitted to Phys. Lett. B. - INW9306II

Cited by in corpus (9)

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• Photon-induced two-nucleon knockout reactions to discrete final states
• Hard Break-Up of Two-Nucleons from the 3He Nucleus
• Damping mechanisms of the Delta resonance in nuclei
• On the treatment of the $\Delta$-contribution in electromagnetic $pp$-knockout reactions
• Nucleon-Nucleon Correlations and Two-Nucleon Currents in Exclusive ($e,e^{\prime }NN$) Reactions