Systematic effects in the determination of the piNN Coupling from pbar p   -> nbar n differential cross section
  We show that the $\pi NN$ coupling constant extracted model-independently from $\bar pp$ charge exchange is subject to a systematic correction, and, more importantly, that the strong absorption in the critical region prevents a determination of the coupling constant to high precision using this process. This attenuates the possible conflict with the value determined from the np charge exchange cross sections. 
T. E. O. Ericson and B. Loiseau