On the Determination of πN Phase Shifts from Isospin Constraints and Fixed t Analyticity

  • I. S. Stefanescu
Conference paper
Part of the Acta Physica Austriaca book series (FEWBODY, volume 23/1981)


This seminar deals with the problem of the determination of the phase of the πN scattering amplitudes from observable quantities (differential cross-sections and polarizations). Its aim is to present, following Ref.[1], conditions on the amplitudes under which a unique construction of the phase can be achieved in some neighbourhood of the forward direction, using constraints coming from analyticity at fixed momentum transfer (t), isospin invariance and unitarity.


Analytic Continuation Meromorphic Function Positivity Property Physical Region Observable Quantity 
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. I.S. Stefanescu, TKP preprint 80/3, to appear in J. Math. Phys..Google Scholar
  2. 2.
    E. Pietarinen, Nucl. Phys. B107 (1976) 21.ADSCrossRefGoogle Scholar
  3. 3.
    R.E. Cutkosky et al., preprint COO-3066–117, LBL-8553 (1979)Google Scholar
  4. D.P. Hodgkinson et al.. Proceedings of the 1976 Conference on Baryonic Resonances, p. 41.Google Scholar
  5. G. Höhler et al.. Handbook of Pion Nucleon Scattering, ZAED report 12–1 (1979).Google Scholar
  6. 5.
    L. Michel, Nuovo Cim. 22 (1961) 203.CrossRefGoogle Scholar
  7. 6.
    J. H. Crichton, Nuovo Cim. 45A (1966) 256.ADSCrossRefGoogle Scholar
  8. 7.
    E. Barrelet, Nuovo Cim. 8A (1972) 331ADSCrossRefGoogle Scholar
  9. F.A. Berends, Nucl. Phys. B64 (1973) 236.ADSCrossRefGoogle Scholar
  10. 8.
    D. Atkinson, G. Mahoux, F.J. Yndurain, Nucl. Phys. B66 (1973) 429.MathSciNetADSCrossRefGoogle Scholar
  11. G.R. Bart, P.W. Johnson, R.L. Warnock, J. Math. Phys.14 (1973) 1558.MathSciNetADSCrossRefGoogle Scholar
  12. G.R. Bart, P.W. Johnson, R.L. Warnock, Nucl. Phys. B72 (1974) 329.MathSciNetADSCrossRefGoogle Scholar
  13. 10.
    D. Atkinson, A.C. Heemskerk, S.D. Swiestra, Nucl. Phys. B109 (1976) 322.ADSCrossRefGoogle Scholar
  14. 11.
    S. Ciulli, C. Pomponiu, I.S. Stefanescu, Phys. Rep. 17C (1975) 135.ADSCrossRefGoogle Scholar
  15. E. Pietarinen, Phys. Scripta 14 (1976)11.ADSCrossRefGoogle Scholar
  16. 13.
    H. Burkhardt, A. Martin, Nuovo Cim. 29A (1975) 141.MathSciNetADSCrossRefGoogle Scholar
  17. 14.
    G. Sommer, Nuovo Cim. 52A (1967) 373.ADSCrossRefGoogle Scholar
  18. 15.
    J. Pierrard et al., Phys. Lett. 57B (1975) 393.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 1981

Authors and Affiliations

  • I. S. Stefanescu
    • 1
  1. 1.Institut für Theoretische KernphysikUniversität KarlsruheGermany

Personalised recommendations