Pion vs. photon absorption on the deuteron

Abstract Using an NN → ΔN transition potential fixed by the reaction pp ↔ dπ+ a good agreement can be obtained also for the reaction γd → pn in the Δ region. Further it is seen that the πNΔ and ϱNΔ parameters of the widely used Bonn potential, fitting the NN sector, yield a transition potential too weak to reproduce the pion production or absorption cross section.

Comment on "Total Cross Section for Photon Absorption by Two Protons inHe3"

Photon absorption on a proton-proton pair inHe3

We calculate the total cross sections for different multiple transitions in photon absorption in a {sup 1}{ital S}{sub 0} {ital pp} pair embedded in a {sup 3}He nucleus. Employing two models, one involving only nucleon degrees of freedom, the other in addition the {Delta}(1232) isobar, we show that the {Delta} gives important effects even in transitions where the photon cannot couple directly to the isobar.