Analyzing power measurements of (d,2He) reactions on light nuclei.

Spin-flip charge-exchange (d, $^{2}\mathrm{He}$) reactions on $^{12}\mathrm{C}$, $^{13}\mathrm{C}$, and $^{14}\mathrm{N}$ were measured at ${E}_{d}=70$ MeV. At forward angles, negative vector analyzing powers of -0.2 to -0.6 were observed for $\ensuremath{\Delta}L=0$ transitions for all targets studied, whereas a positive value was obtained for the transition to the 4.4 MeV excited state of $^{12}\mathrm{B}$ in the $^{12}\mathrm{C}$(d,$^{2}\mathrm{He}$) reaction for which $\ensuremath{\Delta}L=1$ is the main component. Distorted-wave Born-approximation calculations reproduce this $\ensuremath{\Delta}L$ dependence of the analyzing power. The fits to the data for $\ensuremath{\Delta}L=0$ transitions are improved if the two-step processes via d-p-$^{2}\mathrm{He}$ and d-$^{3}\mathrm{He}$-$^{2}\mathrm{He}$ channels are taken into account.