A model for pion Delta electroproduction on the proton

Abstract

We have extended a model for the $γN\to ππN$ reaction to virtual photons and selected the diagrams which have a $Δ$ in the final state. With this model we have evaluated cross sections for the virtual photon cross section as a function of $Q^2$ for different energies. The agreement found with the $γ_v p\toΔ^0π^+$ and $γ_v p\toΔ^{++}π^-$ reactions is good. The sensitivity of the results to $NΔ$ transition form factors is also studied. The present reaction, selecting a particular final state, is an extra test for models of the $γ_{v} N\to ππN$ amplitude. The experimental measurement of the different isospin channels for this reaction are encouraged as a means to unravel the dynamics of the two pions photoproduction processes.