Unitarization and low-energy scattering data
  A method is presented which makes considerably more transparent possible patterns behind low-energy scattering data. In particular, structures associated with resonances, such as locations, widths and heights, become visible with a naked eye. The method is illustrated with a study of the $P$-wave $K\pi$ amplitude. 
Patricia C. Magalh\~aes and Manoel R. Robilotta
hep-ph