New Determination of the AsymptoticD-State-to-S-State Ratio of the Deuteron

The asymptotic $\frac{D}{S}$ ratio of the deuteron, $\eta$, is deduced from new measurements of tensor analyzing powers for sub-Coulomb ($d,p$) reactions. Values of $\eta$ obtained under various experimental conditions (i.e., corresponding to different analyzing powers, bombarding energies, target nuclei, and final states) are consistent within their statistical uncertainties. A weighted average of the individual measurements gives $\eta =0.0256\mathrm{}\pm 0.0004$. This result is compared with predictions obtained from a variety of theoretical models.