Coulomb effects in nucleon-deuteron polarization-transfer coefficients

Coulomb effects in the neutron-deuteron and proton-deuteron polarization-transfer coefficients K_y^y′, K_z^x′, K_y^{x′x′-y′y′}, and K_y^z′z′ are studied at energies above the deuteron breakup threshold. Theoretical predictions for these observables 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 v₁₈ 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.