79 v 1 3 1 M ay 2 00 1 Coulomb effects in nucleon - deuteron polarization - transfer coefficients

Coulomb effects in the neutron-deuteron and proton-deuteron polarization-y are studied at energies above the deuteron breakup threshold. Theoretical predictions for these ob-servables are evaluated in the framework of the Kohn Variational Principle using correlated basis functions to expand the three-nucleon scattering wave function. The two-nucleon Argonne v 18 and the three-nucleon Urbana IX potentials are considered. In the proton-deuteron case, the Coulomb interaction between the two protons is included explicitly and the results are compared to the experimental data available at E lab = 10, 19, 22.7 MeV. In the neutron-deuteron case, a comparison to a recent measurement of K y ′ y by Hempen et al. at E lab = 19 MeV evidences a contribution of the calculated Coulomb effects opposite to those extracted from the experiment.