Calculation of two-photon exchange effects for $Δ$ production in electron-proton collisions
Abstract
Description
We present an evaluation of a two-photon exchange correction to the cross section for unpolarized $Δ$ isobar production in electron-proton collisions, using a relativistic, crossing symmetric and gauge invariant approach. The calculated box and crossed-box diagrams include nucleon and $Δ$ intermediate states. We find a relation between the angular nonlinearity of the two-photon exchange contribution and the value of the $γΔΔ$ coupling constant.
10 pages, 2 figures, RevTeX4; more detailed discussion, results unchanged; to be published in Nucl.Phys.A
10 pages, 2 figures, RevTeX4; more detailed discussion, results unchanged; to be published in Nucl.Phys.A