Proton elastic form factor ratios to Q{sup 2}=3.5 GeV{sup 2} by polarization transfer

Journal Article · Sun May 01 04:00:00 EDT 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.71.055202· OSTI ID:20698695

Punjabi, V ^[1]; Perdrisat, C F; Gerstner, G; Pentchev, L; Rutledge, G; Strauch, S; Wijesooriya, K ^[2]; Aniol, K A; Epstein, M B; Margaziotis, D J ^[3]; Baker, F T; Templon, J A ^[4]; Berthot, J; Bertin, P Y; Besson, A; Fonvieille, H; Jaminion, S; Laveissiere, G ^[5]; Bertozzi, W; Chai, Z ^[6]

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1. Norfolk State University, Norfolk, Virginia 23504 (United States)
2. College of William and Mary, Williamsburg, Virginia 23187 (United States)
3. California State University, Los Angeles, Los Angeles, California 90032 (United States)
4. University of Georgia, Athens, Georgia 30602 (United States)
5. Universite Blaise Pascal/CNRS-IN2P3, F-63177 Aubiere (France)
6. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); and others

The ratio of the proton elastic electromagnetic form factors, G{sub Ep}/G{sub Mp}, was obtained by measuring P{sub t} and P{sub l}, the transverse and longitudinal recoil proton polarization components, respectively, for the elastic e{sup {yields}}p{yields}ep{sup {yields}}reaction in the four-momentum transfer squared range of 0.5 to 3.5 GeV{sup 2}. In the single-photon exchange approximation, G{sub Ep}/G{sub Mp} is directly proportional to P{sub t}/P{sub l}. The simultaneous measurement of P{sub t} and P{sub l} in a polarimeter reduces systematic uncertainties. The results for G{sub Ep}/G{sub Mp} show a systematic decrease with increasing Q{sup 2}, indicating for the first time a definite difference in the distribution of charge and magnetization in the proton. The data have been reanalyzed and their systematic uncertainties have become significantly smaller than those reported previously.

• OSTI ID: 20698695
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 5 Vol. 71; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
DISTRIBUTION
ELECTROMAGNETIC FORM FACTORS
ELECTRON REACTIONS
ELECTRON-PROTON INTERACTIONS
ELECTRONS
FOUR MOMENTUM TRANSFER
MAGNETIZATION
PHOTONS
POLARIZATION
PROTONS
RECOILS