On Delta resonance contribution to two-photon exchange amplitude

Abstract

We consider two-photon exchange (TPE) in the elastic electron-proton scattering and study the contribution arising from the production of Delta(1232) resonance in the intermediate state. We calculate all three TPE amplitudes (generalized form factors), and find that the Delta contribution mainly influences generalized electric form factor (contrary to the elastic contribution, which affects magnetic form factor), and the effect grows with Q^2. If the corresponding correction is applied to the recent polarization transfer measurements of proton form factors, their results will change markedly. Thus we suggest that TPE corrections due to inelastic intermediate states are important to polarization experiments at high Q^2, and should not be neglected.

6 pages, 7 figures; Eq.(13) corrected, Fig. 5 changed, other minor changes; to be published in Phys.Rev.C

References in corpus (5)

• Global analysis of proton elastic form factor data with two-photon exchange corrections
• Two-photon exchange in dispersion approach
• Contribution of spin 1/2 and 3/2 resonances to two-photon exchange effects in elastic electron-proton scattering
• Perturbative QCD predictions for two-photon exchange
• Phenomenological analysis of two-photon exchange effects in proton form factor measurements