Speaker
Dmitrij Siemens
Summary
Elastic pion-nucleon scattering is analyzed in the framework of chiral perturbation theory
at the full one-loop order with explicit $\Delta$ degrees of freedom.
The analysis is performed in the small scale expansion within the heavy baryon and
a covariant approach based on the extended on mass-shell renormalization scheme.
The pertinent low-energy constants contributing to the pion-nucleon scattering amplitude
are extracted from fits to experimental scattering data as well as subthreshold parameters.
A novel approach to estimate the theoretical uncertainty based on the truncation of the chiral
series is employed in the fitting procedure. The obtained results for the various pion-nucleon
scattering observables are presented and discussed.
