The Effect of the D-State of the Deuteron in (d,p) Reactions.

The [3]D[1] state of the deuteron was taken into account in the distorted-wave Born approximation theory of deuteron stripping reactions. An approximation was used for the radial part of the D-wave in momentum space and the local energy approximation for finite range effects in the S-state part of the reaction scattering amplitude was extended to the D-state part. The angular dependence of the D-wave is accounted for exactly in the formalism of the distorted-wave theory. The resulting calculations at deuteron energies below 20 MeV show that the D-state effect in the differential cross-section is strongly dependent on l and j and its magnitude increases with l. The j-dependence of the effect improves significantly the theoretical fit to the small angle j-dependence observed in l = 3 angular distributions. This is particularly noticeable when configuration mixing effects are relatively small in both the 5-/2and the 7-/2 transitions. The j-dependence of the effect is also in qualitative agreement with the small angle j-dependence observed in Id transitions. However the inclusion of the D-state does not improve the agreement with the large angle j-dependence in l = 1 angular distributions. Using a surface reaction model it is shown that the magnitude of the D-state effect, relative to the S-state, in the angular distribution increases with the Q-value of the reaction and decreases with an increase in the target nucleus mass and the reaction energy. It is proved that in the absence of spin-dependent distortion the proton polarization is more sensitive than the deuteron efficiency vector to those j-dependent effects, introduced by the D-state, which do not obey the simple sign rule valid for the S-state contribution