Two Photon Exchange Corrections to the Electromagnetic Form Factors of the Proton*

I am going to discuss two-photon-exchange corrections to the electromagnetic form factors of the proton. The proton form factors give fundamental information about the internal structure of the proton and have been traditionally extracted from the electron-proton differential cross section assuming the dominance of one-photon exchange (leading order (LO) terms in the electromagnetic coupling). However, the two principal experimental techniques for determining the form factors yield notable discrepancies under this approximation. I will discuss how corrections at next-to-leading order (NLO) in the electromagnetic strength, such as those from two-photon exchange (TPE), may help resolve this discrepancy. In particular, I will discuss how to consistently combine TPE corrections at the hadronic and parton level which represent the low-mass intermediate state contributions in terms of hadronic transition form factors and the high-mass intermediate states in terms of generalized parton distributions (GPDs) respectively. This work may help improve our knowledge of the internal structure of the proton at intermediate to small energy scales.