Determination of the chiral coupling constants c(3) and c(4) in new pp and np partial-wave analyses

As a first result of two new partial-wave analyses, one of the pp and another one of the np scattering data below 500 MeV, we report a study of the long-range chiral two-pion exchange interaction which contains the chiral coupling constants c(1), c(3), and c(4). By using as input a theoretical value for c(1) we are able to determine in pp as well as in np scattering accurate values for c(3) and c(4). The values determined from the pp data and independently from the np data are in very good agreement, indicating the correctness of the chiral two-pion exchange interaction. The weighted averages are c(3)=-4.78(10)/GeV and c(4)=3.96(22)/GeV, where the errors are statistical. The value of c(3) is best determined from the pp data and that of c(4) from the np data