Two-photon exchange in elastic electron-proton scattering
Two-photon exchange contributions to unpolarized and polarized elastic electron-proton scattering cross sections are evaluated taking into account nucleon finite size effects using realistic form factors. Contributions from nucleon elastic intermediate states are found to have a strong angular dependence, which partially resolves the discrepancy between Rosenbluth and polarization transfer measurements of the proton electric to magnetic form factor ratio. Two-photon contributions to the longitudinal and transverse polarizations are generally found to be small. A comparison is made of two-photon exchange effects with existing data on the ratio of e+ p to e- p cross sections, which is predicted to be enhanced at backward angles.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research (ER) (US)
- DOE Contract Number:
- AC05-84ER40150
- OSTI ID:
- 839017
- Report Number(s):
- JLAB-THY-04-76; DOE/ER/40150-3290; TRN: US0501577
- Resource Relation:
- Conference: 8th Workshop On Electron Nucleus Scattering, Elba (IT), 06/21/2004--06/25/2004; Other Information: PBD: 1 Feb 2005
- Country of Publication:
- United States
- Language:
- English
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