Kaonic Nuclear Systems KbarN and KbarNN as Decaying States
  The formation spectra of model KbarN and KbarNN systems formed by (K-, n) reactions are investigated in order to obtain a theoretical basis for a proper interpretation of experimental data concerning kaonic nuclear quasi-bound states. It has been clarified that the experimentally observable kaonic nuclear state K-pp should be regarded as the decaying state introduced by Kapur-Peierls, which is different from the pole state solution of the Faddeev equation. 
Y. Akaishi, K.S. Myint and T. Yamazaki