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arXiv · 1506.02682

Two photon exchange amplitude with πN intermediate states: spin-1/2 and spin-3/2 channels

Dmitry Borisyuk·Alexander Kobushkin
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Abstract

We calculate two-photon exchange (TPE) amplitudes for the elastic electron-proton scattering, and take into account intermediate hadronic states containing πN system with total angular momentum 1/2 or 3/2, which includes 8 different channels. This is the improvement of our previous calculation, where only the πN states with quantum numbers of Δ(1232) resonance were included. The results show good consistency with recent experimental data. At high Q^2, newly-calculated contributions affect the correction to the measured proton form factor ratio μG_E/G_M. The total correction becomes somewhat smaller compared to our previous work, but is still significant and grows approximately linearly with Q^2. Comparing contributions of different channels, we found that larger contributions come from the channels with quantum numbers of lightest resonances.

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Dmitry Borisyuk, Alexander Kobushkin. 2015-06-08. Two photon exchange amplitude with πN intermediate states: spin-1/2 and spin-3/2 channels. https://doi.org/10.1103/physrevc.92.035204

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