Pole structure from energy-dependent and single-energy fits to $\pi N$   elastic scattering data
  The pole structure of the current GW/SAID partial-wave analysis of elastic $\pi N$ scattering and $\eta N$ production data is studied. Pole positions and residues are extracted from both the energy-dependent and single-energy fits, using two different methods. For the energy-dependent fits, both contour integration and a Laurent+Pietarinen approach are used. In the case of single-energy fits, the Laurent+Pietarinen approach is used. Errors are estimated and the two sets of results are compared to other recent and older fits to data. 
Alfred \v{S}varc, Mirza Had\v{z}imehmedovi\'c, Hedim Osmanovi\'c,   Jugoslav Stahov, Ron L. Workman
nucl-th