6533b821fe1ef96bd127b6be
RESEARCH PRODUCT
Two-photon exchange corrections to elastic e− -proton scattering: Full dispersive treatment of πN states at low momentum transfers
Oleksandr TomalakMarc VanderhaeghenBarbara Pasquinisubject
Physics010308 nuclear & particles physicsScatteringMomentum transferScattering lengthClassification of discontinuities01 natural sciencesScattering amplitudeMomentumDispersion relation0103 physical sciencesAtomic physics010306 general physicsParametrizationdescription
We evaluate the pion-nucleon intermediate-state contribution to the two-photon exchange (TPE) correction in the elastic electron-nucleon scattering within a dispersive framework. We calculate the contribution from all $\ensuremath{\pi}N$ partial waves using the MAID parametrization. We provide the corresponding TPE correction to the unpolarized $ep$ scattering cross section in the region of low momentum transfer ${Q}^{2}\ensuremath{\lesssim}0.064\text{ }\text{ }{\mathrm{GeV}}^{2}$, where no analytical continuation into the unphysical region of the TPE scattering amplitudes is required. We compare our result in the forward angular region with an alternative TPE calculation, in terms of structure functions, and find a good agreement, indicating a small contribution at low ${Q}^{2}$ due to discontinuities beyond $\ensuremath{\pi}N$. We also compare our results with empirical fits.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-05-01 | Physical Review D |