Neutron Blocking inα-Particle-Transfer Reactions

The ($d$, ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$) $\alpha$-transfer reaction on several even-$A$ and odd-$A$ tin isotopes has been investigated at $E_d=35\mathrm{}$ MeV. A significant reduction (∼ factor 2) in transition strength is observed for the odd-$A$ target nuclei. This reduction is attributed to the "blocking" effect of unpaired nucleons and is comparable to that observed in ($p, t$) reactions.