Phase-Shift Definition for Pion-Nucleon Scattering from Chiral Perturbation Theory
نویسنده
چکیده
Chiral Perturbation Theory is considered as a very precise method when applied to pion-nucleon scattering near threshold and in the unphysical region since in these cases the pion momenta are small. In this framework, third order calculation yields a non-relativistic scattering amplitude with nine free parameters. From the fact that the resulting partial-wave amplitudes do not respect elastic unitarity relation, one has that the phase-shift definition is ambiguous. In this article, we present the comparison of the model with experimental data for two different phase-shift formulas and we conclude that the results are very sensitive to phase-shift definition.
منابع مشابه
Ju n 19 97 PERIPHERAL NUCLEON – NUCLEON PHASE SHIFTS AND CHIRAL SYMMETRY ∗
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