A NEW MEASUREMENT OF THE (P)OVER-BARP-](N)OVER-BARN CHARGE-EXCHANGE DIFFERENTIAL CROSS-SECTION AT LEAR

We have measured the <p(p)over bar> --> <n(n)over bar> charge-exchange differential cross-section at two incoming (p) over bar momenta (601. 5 and 1202 MeV/c) at the CERN Low Energy Antiproton Ring. After review ing the experimental method, the data analysis is fully detailed, and the results on the whole statistics available in the centre of mass fo rward hemisphere are given. A precision in the absolute normalisation of 2% and 4% at 601.5 and 1202 MeV/c respectively is achieved, while o ver most of the angular range the point-to-point error is lower than 1 %. The forward peak associated with the nearby pion pole and a dip-bum p structure are accurately measured, The ''Chew'' extrapolation to the pion-pole suggests a ''low'' value for the pi NN coupling constant g( c)(2). (C) 1997 Elsevier Science B.V.