Resonance-parton duality in (e,e′π) off nucleons

Regge-pole-based descriptions of pion-electroproduction on nucleons have given a very good description of the longitudinal components of the cross sections. However, these very same models grossly underestimate the transverse components. A related problem appears in QCD-based scaling arguments that predict the predominance of longitudinal over transverse electroproduction of pions by terms ∝Q2. However, data from JLAB, Cornell, and DESY, covering a wide kinematical range 12GeV) nucleon resonances to pion production. The coupling strengths and form factors are obtained through resonance-parton duality. We show that in a wide range of electron energies and four-momentum transfers such a model describes all the available data very well.