Propagation of a deuteron in nuclear matter and the spin dependence of the deuteron optical potential

The propagation of a deuteron through nuclear matter is examined in terms of a simple nonlocal but separable potential for the $n-p$ interaction. It is found that the binding energy of the deuteron in nuclear matter depends strongly on the relative orientation of the deuteron spin and center-of-mass momentum, when both the Pauli exclusion principle and the tensor force component in the neutron-proton interaction are included in the calculation. A thorough discussion of the physical mechanism involved is presented. It is shown that this effect is associated with the presence of a new type of spin dependent interaction of the $T_p$ type, in the deuteron-nucleus optical potential. The nuclear matter calculations are applied to the realistic case of a deuteron scattered by a heavy nucleus through a simple model which is valid for deuteron incident energies in excess of 100 MeV. The $T_p$ force thus produced is found to have a non-negligible strength over a wide range of high incident deuteron energies and to be very sensitive to high momentum components of the nucleon-nucleon interaction. The mechanism examined here is also expected to generate a $T_p$ force and a modified $T_R$ force at low energies.