Sub-barrier one- and two-neutron pickup measurements in ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{93}$Nb, ${}_{}{}^{98,100}{}_{}{}^{}\mathrm{Mo}$ reactions at 180°

Excitation functions for sub-barrier one- and two-neutron pickup reactions were measured for ${\mathit{E}}_{\mathrm{lab}}$≤106 MeV in ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{93}$Nb, ${}_{}{}^{98,100}{}_{}{}^{}\mathrm{Mo}$ systems by detecting targetlike recoils at 0° using a recoil mass spectrometer. The slopes of transfer probability vs distance of closest approach are in good agreement with binding energies, indicating the absence of a ‘‘slope anomaly.’’ Angle-integrated transfer cross sections derived from measured 180° yields are consistent with enhancements in previously measured fusion yields for the ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{98,100}$Mo systems.