Scattering of high-energy positrons from protons
Abstract
Positron and electron beams from the Stanford Mark III linear accelerator have been used to investigate the importance of two-photon exchanges in electron scattering from the proton. The scattering cross sections for positrons and electrons have been compared at 200 and 300 MeV for q^2 (the square of the four-momentum transfer) from 0.3 to 5.2 F^-2. The results show no evidence of anomalous two-photon effects and verify the correctness of the first Born approximation form factor analysis to within a few percent or better for this range of q^2. The variation of the cross sections with q^2 has also been measured with high accuracy. The specific ionizations of 300-MeV positrons and electrons in hydrogen at one atmosphere have been compared in the course of the experiment, and found to be equal to within ±0.3%.
Additional Information
©1962 The American Physical Society. Received 25 June 1962. It is a pleasure to thank Professor W. K. H. Panofsky for his aid and encouragement during the execution of the experiment, Professor S. D. Drell and Professor Y. S. Tsai for advising us on theoretical matters, and Dr. F. Bumiller for discussions concerning the Faraday cup efficiency and the performance of the rotating coil and the momentum-analyzing systems. The hydrogen target was designed and constructed by E. A. Allton, R. Alvarez, and L. Hand. R. G. Gilbert, L. L. Combs, and T. M. Sartain gave generous assistance in obtaining the positron beam, while L. Boyer, E. Pathway, and J. Grant helped with the construction of much of the apparatus.Files
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Additional details
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- 3195
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- CaltechAUTHORS:YOUpr62
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2006-05-19Created from EPrint's datestamp field
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2021-11-08Created from EPrint's last_modified field