Proton form factors and two-photon exchange in elastic electron-proton scattering

Journal Article · Fri May 15 00:00:00 EDT 2015 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778815020234· OSTI ID:22472293

Arrington, J. ^[1]; Barkov, L. M. ^[2]; Vries, H. de ^[3]; Gauzshtein, V. V. ^[4]; Golovin, R. A.; Gramolin, A. V.; Dmitriev, V. F.; Zhilich, V. N.; Zevakov, S. A.; Kaminsky, V. V.; Lazarenko, B. A.; Mishnev, S. I.; Muchnoi, N. Yu.; Neufeld, V. V.; Rachek, I. A.; Sadykov, R. Sh. ^[2]; Stibunov, V. N. ^[4]; Toporkov, D. K. ^[2]; Holt, R. J. ^[1]; others, and

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1. Argonne National Laboratory (United States)
2. Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)
3. NIKHEF (Netherlands)
4. National Research Tomsk Polytechnic University, Physical-Technical Institute (Russian Federation)

Proton electromagnetic form factors are among the most important sources of information about the internal structure of the proton. Two different methods for measuring these form factors, the method proposed by Rosenbluth and the polarization-transfer method, yield contradictory results. It is assumed that this contradiction can be removed upon taking into account the hard part of the contribution of two-photon exchange to the cross section for elastic electron-proton scattering. This contribution can measured experimentally via a precision comparison of the cross sections for the elastic scattering of positrons and electrons on protons. Such a measurement, performed at the VEPP-3 storage ring in Novosibirsk at the beam energies of 1.6 and 1.0 GeV for positron (electron) scattering angles in the ranges of θ{sub e} = 15°–25° and 55°–75° in the first case and in the range of θ{sub e} = 65°–105° in the second case is described in the present article. Preliminary results of this experiment and their comparison with theoretical predictions are described.

• OSTI ID: 22472293
• Journal Information: Physics of Atomic Nuclei, Vol. 78, Issue 3; Other Information: Copyright (c) 2015 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7788
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CROSS SECTIONS
ELASTIC SCATTERING
ELECTROMAGNETIC FORM FACTORS
ELECTRON-POSITRON INTERACTIONS
ELECTRON-PROTON INTERACTIONS
ELECTRONS
GEV RANGE
PHOTONS
POLARIZATION
POSITRONS
PROTONS
VEPP-3