Phase-shift definition for pion-nucleon scattering from chiral perturbation theory
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.
Main Authors: | , |
---|---|
Format: | Digital revista |
Language: | English |
Published: |
Sociedade Brasileira de Física
2004
|
Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332004000200024 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|