Elsevier

Nuclear Physics A

Volume 416, 26 March 1984, Pages 193-207
Nuclear Physics A

Pion-nucleon elastic scattering

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Abstract

Pion-Nucleon scattering is reviewed. Positive results include: 1) good agreement between the πN resonance parameters of the KarlsruheHelsinki K-H, and Carnegie-Mellon-Berkeley, CMU-LBL, partial wave analyses; 2) no sizable isospin violation near the Roper resonance; 3) a 1° – 2° isospin violation in the region of the Δ (1232); 4) the u- and d- quark mass difference is small, with md > mu; 5) forward dispersion relation predictions agree with experiment up to 300 GeV/c; 6)there are no good candidates for πN hermaphrodites; 7) the Isqur-Karl quark model calculations are useful up to m ⋍ 1800 MeV. Negative findings are: 1) there is urgent need for spin rotation measurements to verify the correct use of theoretical constraints in a11 partial wave analyses; 2) existing data is insufficient to establish the fate of 24 πN resonance candidates; 3) 3 strong and 7 weak πN resonances with mass above 1800 MeV predicted by the Isgur-Karl quark model are not seen; 4) the experimental result for the πN σ-term is 64 ± 8 MeV while the QCD inspired prediction is 35 ± 5 MeV. Finally, there is some evidence for clustering of πN resonance poles in the complex energy plane, it is unknown if this is accidental or new physics.

References (44)

  • M. Gell-Mann

    Phys. Lett.

    (1964)
  • R.E. Cutkosky et al.

    Phys. Rev.

    (1979)
    R.E. Cutkosky et al.

    Phys. Rev.

    (1979)
    R.E. Cutkosky et al.

    Phys. Rev.

    (1979)
    R.E. Cutkosky
  • R.M. Brown

    Nucl. Phys.

    (1976)
    R.M. Brown

    Nucl. Phys.

    (1978)
  • M. Sadler

    Contr. Few Body X

    (1983)
  • LAMPF proposal #806 by UCLAG (= UCLA-CUA-LAMPF-ACU-GWU)...
  • V.S. Zidell et al.

    Phys. Rev.

    (1980)
  • J.C. Alder

    Phys. Rev.

    (1983)
  • A de Rújula et al.

    Phys. Rev.

    (1975)
  • G. Zweig

    CERN reports 8131/TH.461 and 8419/TH.412

    (1964)
  • More appropriate would be “color degree of...
  • M. Roos

    Review of Particle Properties

    Phys. Lett.

    (1982)
  • G. Höhler et al.

    Handbook of pion-nucleon scattering

    Physik Daten

    (1979)
    R. Koch et al.

    Low energy update

    Nucl. Phys.

    (1980)
  • R. Ayed

    CEA-N-1921

    (1976)
  • V.V. Abaev

    Leningrad Nucl. Phys. Inst. preprint No 438

    (1978)
  • P.L. Csonka et al.

    Phys. Rev.

    (1966)
  • K.J. Foley

    Phys. Rev.

    (1969)
  • L.A. Fajardo

    Phys. Rev.

    (1981)
  • J.P. Burq

    Phys. Lett.

    (1982)
    J.P. Burq

    Phys. Lett.

    (1978)
  • G. Höhler et al.

    KFK 3027

    (1980)
  • V.S. Bekrenev

    Nucl. Phys.

    (1981)
  • V.V. Abaev

    Z. Phys.

    (1983)
  • V.S. Bekrenev

    Contr. Few Body X

    (1983)
  • Cited by (0)

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