NUCLEON-NUCLEON AND FEW-BODY STUDIES A COMPLETE SET OF IN-PLANE SPIN-TRANSFER COEFFICIENTS FOR SMALL ANGLE pp ELASTIC SCATTERING

Current potential models1 of the nucleon-nucleon (NN) interaction can describe much of the lowand intermediate-energy NN scattering database with a X 2 per datum fairly close to 1. In spite of these successes, however, there remains significant controversy over the value of one of the most fundamental parameters in such models, the pion-nucleon coupling constant g:. Difficulties encountered initially in reproducing both the pp scattering data and the ground-state properties of the deuteron2 led to speculation as to whether this coupling could be strongly charge-dependent.3 Though later analyses of the NN (both pp and np) (Ref. 1) and ?rN (Ref. 4) data showed no clear signature for chargedependence, the large value for gZk extracted in a recent study of the np cross section at back angles5 has only served to muddy the waters further. An additional complication, and one whose severity is difficult to gauge, arises from the fact that those who model the interaction have generally employed different criteria for data selection, different conventions for renormalizing data sets, and have emphasized different energy ranges in their analysis. Thus, discrepancies at the few percent level for remain, even when only pp scattering is ~onsidered.~ 7'