Elastic and Inelastic Polarization Effects Observed with the Argonne Effective Mass Spectrometer

  • D. S. Ayres
  • D. Cohen
  • R. Diebold
  • S. L. Kramer
  • A. J. Pawlicki
  • A. B. Wicklund
Part of the Studies in the Natural Sciences book series (SNS, volume 12)


The Argonne polarized proton beam has been used together with the Effective Mass Spectrometer to study several different aspects of pp and pn interactions. The polarization asymmetry for pn elastic scattering was measured for the first time above cyclotron energies. The results show that both I = 0 and I = 1 exchanges have important contributions to the t-channel single-flip amplitudes. While the I = 1 amplitude has the energy dependence expected, the I = 0 contribution falls much faster with energy. For Rp→Δ++n we find a left-right production asymmetry of about 40% for −t ≥ 0.5 GeV2, independent of energy. Absorbed one-pion-exchange together with quark-model calculations give a qualitative explanation of the Δ++ decay distributions and their dependence on the beam polarization. In the diffractive process pp→Δ++πp we observe asymmetries in the low mass Δπ system that can be described by interference between an S-wave Deck background and a P-wave N*1470 resonance contribution.


Quark Model Density Matrix Element Recoil Proton Spin Dependence Production Amplitude 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    A. Gaidot et al Phys. Letters 61B, 103 (1976).CrossRefGoogle Scholar
  2. 2.
    R. Diebold et al Phys. Rev. Letters 35, 632 (1975).CrossRefGoogle Scholar
  3. 3.
    For more details on the spectrometer, see, for example, L. Ambats et al Phys. Rev. D9, 1179 (1974)•Google Scholar
  4. 4.
    F. Halzen and G. Thomas, Phys. Rev. D10, 344 (1974)•Google Scholar
  5. 5.
    M. Borghini et al Phys. Letters 31B, 405 (1970).CrossRefGoogle Scholar
  6. 6.
    L. Durand and F. Halzen, Nucl. Phys. B104 317 (1976).Google Scholar
  7. 7.
    R.D. Field and P.R. Stevens, ANL-HEP-CP-75–73, p 28.Google Scholar
  8. 8.
    J. Dash and H. Navelet, Phys. Rev. D13, 1940 (1976).Google Scholar
  9. 9.
    A.C. Irving, Nucl. Phys. B101, 163 (1975).CrossRefGoogle Scholar
  10. 10.
    C. Bourrely, A. Martin, and J. Soffer, preprint (1976).Google Scholar
  11. 11.
    A.B. Wicklund, Section XV of ANL/HEP 7440, Section III of ANL/HEP 75–02, and Proc. of Symp. on High Energy Physics with Polarized Beams and Targets, AIP Conf. Proc. 35, p 198 (1976); R. Diebold, ibid, p 92.Google Scholar
  12. 12.
    R.D. Field, Some Aspects of Two Body Phenomenology (XVII Int. Conf. on High Energy Physics, London 1974 ) p I - 185.Google Scholar
  13. 13.
    G.C. Fox and C. Quigg, Production Mechanisms of Two-to-Two Scattering Processes at Intermediate Energies (Ann. Rev. of Nucl. Sci., Vol. 23, 1973 ) p 219.CrossRefGoogle Scholar
  14. 14.
    P.K. Williams, Phys. Rev. D1, 1312 (1970).Google Scholar
  15. 15.
    S.L. Kramer et al Phys. Rev. Lett. 33, 505 (1974).CrossRefGoogle Scholar
  16. 16.
    D.J. Herndon et al Phys. Rev. D1l, 3183 (1975).Google Scholar

Copyright information

© Springer Science+Business Media New York 1977

Authors and Affiliations

  • D. S. Ayres
    • 1
  • D. Cohen
    • 1
  • R. Diebold
    • 1
  • S. L. Kramer
    • 1
  • A. J. Pawlicki
    • 1
  • A. B. Wicklund
    • 1
  1. 1.Argonne National LaboratoryArgonneUSA

Personalised recommendations