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Invariant Amplitudes for Pion Electroproduction

143   0   0.0 ( 0 )
 نشر من قبل Lothar Tiator
 تاريخ النشر 2007
  مجال البحث
والبحث باللغة English
 تأليف B. Pasquini




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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.



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