EFFECTS OF NONNUCLEONIC DEGREES OF FREEDOM IN THE D((P)OVER-RIGHT-ARROW,GAMMA)HE-3 AND P((D)OVER-RIGHT-ARROW,GAMMA)HE-3 REACTIONS

Measurements of the D((p) over right arrow, gamma)He-3 and p((d) over right arrow, gamma)He-3 reactions below E(p,d) = 80 keV are compared t o the results of calculations based on correlated hyperspherical harmo nic wave functions obtained from realistic interactions with full incl usion of Coulomb distortion in the initial continuum state, and a nucl ear current operator with one- and two-body components. Dramatic effec ts due to the tensor force and the associated two-body (meson-exchange ) interaction currents are observed in the vector and, to some extent, tensor analyzing powers for the first time. The extrapolation to zero energy leads to an S-factor value of S(E = 0) = 0.165 +/- 0.014 eV b, in reasonable agreement with theory.