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Title: Measurement of the Two-Photon Exchange Contribution to the Elastic e±p Scattering Cross Sections at the VEPP-3 Storage Ring

The ratio of the elastic e+p to ep scattering cross sections has been measured precisely, allowing the determination of the two-photon exchange contribution to these processes. This neglected contribution is believed to be the cause of the discrepancy between the Rosenbluth and polarization transfer methods of measuring the proton electromagnetic form factors. The experiment was performed at the VEPP-3 storage ring at beam energies of 1.6 and 1.0 GeV and at lepton scattering angles between 15° and 105°. The data obtained show evidence of a significant two-photon exchange effect. Furthermore, the results are compared with several theoretical predictions.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [3] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [3] ;  [1] ;  [1] ;  [1] ;  [1] ;  [4] ;  [3] ;  [5] ;  [1] ;  [3]
  1. Budker Institute of Nuclear Physics, Novosibirsk (Russia)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
  3. Budker Institute of Nuclear Physics, Novosibirsk (Russia); Novosibirsk State Univ., Novosibirsk (Russia)
  4. Tomsk Polytechnic Univ., Tomsk (Russia)
  5. Nikhef, Amsterdam (The Netherlands)
Publication Date:
Grant/Contract Number:
AC02-06CH11357; MK-525.2013.2
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 114; Journal Issue: 6; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
Russian Federation, Ministry of Education and Science; USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
OSTI Identifier:
1392573
Alternate Identifier(s):
OSTI ID: 1180395