Angular distributions of cross sections and tensor analyzing powers have been measured for ground state transitions in ${}_{}{}^{95}{}_{}{}^{}\mathrm{Mo}$(d,t${)}^{94}$Mo, ${}_{}{}^{119}{}_{}{}^{}\mathrm{Sn}$(d,t${)}^{118}$Sn, and ${}_{}{}^{149}{}_{}{}^{}\mathrm{Sm}$(d,t${)}^{148}$Sm for deuteron energies below the Coulomb barrier. Exact, finite-range distorted-wave Born approximation analyses of these data have been made using both the S- and D-state amplitudes for the three-nucleon systems. A best fit of the data gives ${\mathit{D}}_2$(t)=-0.217±0.010 ${\mathrm{fm}}^2$ and ${\mathrm{\eta }}_{\mathit{t}}$=-0.043±0.002, significantly lower than previous experimental determinations, and in agreement with a recent theoretical prediction of ${\mathrm{\eta }}_{\mathit{t}}$=-0.046±0.001.

• Received 13 November 1991

DOI:https://doi.org/10.1103/PhysRevLett.68.1112