Crossing and physical partial-wave amplitudes

1972
34 pages
Published in:
  • Nuovo Cim.A 7 (1972) 363-396

Citations per year

197219851998201120220246810
Abstract: (Springer)
We study the implications of crossing and analyticity properties on partial-wave amplitudes in the physical region. We first show the physical interest of the ππ equations recently written by Roy; comparison with the Chew-Mandelstam equations is particularly instructive, and we show how these equations can be used:a) to construct low-energy amplitudes in practice, andb) to check the consistency of experimental data (adirect method for solving the «up-down» ambiguity and calculatings-wave scattering lengths is obtained). We then reconsider the Martin inequalities and the sum rules from which they are derived, and show that they can be used in a more powerful way. Our considerations and results give strong support to the model of Le Guillou, Morel and Navelet for ππs-waves. We finally give the general method for deriving physical-region crossing equations for arbitrary processes, in particular πN→πN.
  • partial wave: analytic properties
  • symmetry: crossing
  • pi pi: interaction
  • interaction: pi pi
  • pi k: interaction
  • interaction: pi k
  • pi nucleon: elastic scattering
  • elastic scattering: pi nucleon
  • dispersion relation
  • mandelstam representation
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