Publication Date:
2007
abstract:
The invariant amplitudes for pion electroproduction on the nucleon are evaluated by dispersion relations at constant t with MAID as input for the imaginary parts of these amplitudes. In the threshold region these amplitudes are confronted with the predictions of several low-energy theorems derived in the soft-pion limit. In general agreement with chiral perturbation theory, the dispersive approach yields large corrections to these theorems because of the finite pion mass.
Iris type:
1.1 Articolo in rivista
Keywords:
pion electroproduction; dispersion relations; nucleon excitation spectrum
List of contributors:
Pasquini, Barbara; D., Drechsel; L., Tiator
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