Relativistic treatment of spin-transfer observables in quasielastic ($\vec{\bf p},\vec{\bf n}$) scattering

We calculate all spin-transfer observables for the quasielastic ($\vec{p},\vec{n}$) reaction in a relativistic plane-wave impulse approximation. The nuclear-structure information is contained in a large set of nuclear-response functions that are computed in nuclear matter using a relativistic random-phase approximation to the Walecka model. A reduced value of the nucleon mass in the medium induces important dynamical changes in the residual isovector interaction relative to its nonrelativistic counterpart. As a result, good agreement is found for all spin observables --- including the spin-longitudinal to spin-transverse ratio --- when compared to the original (q=1.72~fm^{-1}) NTOF experiment. In contrast, the spin-longitudinal to spin-transverse ratio is underpredicted at q=1.2~fm^{-1} and overpredicted at q=2.5~fm^{-1}. We comment on the role of distortions as a possible solution to this discrepancy.