SPIN TRANSFER-COEFFICIENTS FOR PP ELASTIC-SCATTERING AT 200 MEV - IMPLICATIONS FOR THE PI-NN COUPLING-CONSTANT

A series of precision measurements of the spin-transfer coefficients t hat characterize pp elastic scattering at 200 MeV has been completed r ecently at IUCF. These new data span a kinematic regime chosen specifi cally to maximize sensitivity to the value of the neutral pi NN coupli ng constant. The data provide strong support for modern potential mode ls of the NN interaction in which a weaker pion coupling (g(0)(2)/4 pi approximate to 13.6) is employed. Moreover, calculations within the f ramework of the Full Bonn potential suggest that a reduction in g(0)(2 )/4 pi from 14.4 to 13.6 would significantly improve agreement between model predictions and our new results.