Determination of the charged pion-nucleon coupling constant from overlinepp → overlinenn differential cross-section

A recent experiment at LEAR, the CERN Low Energy Antiproton Ring, has provided very precise differential cross-section data for the overlinepp → overlinenn charge-exchange reaction. Extrapolating the data to the pion pole we have determined the charged-pion coupling constant to be f_c² = 0.071 ± 0.002 from the data at 601 MeV/ c. Details of the fitting procedure are given, as well as results obtained when applying the same method to recent np → pn data.