(p,t) Excitations of Removal and Addition Types of Quadrupole-Pairing Vibrational States in Even Nd Isotopes

Strong $L=2\mathrm{}$ transitions to the removal type of quadrupole-pairing vibrational states with $Q=-(8-10)\mathrm{}$ MeV, observed in ($p,t$) reactions on all stable Nd isotopes with 52-MeV protons, are shown to be well accounted for by one-step distorted-wave Born-approximation calculations. Compared with these, the transitions to the $2_1^{}{}_{}{}^{+}$ (addition type of quadrupole pairing) states of $N>~82$ isotopes, which are found to be much weaker and have quite different angular distributions, are shown to be reasonably accounted for in terms of two step coupled-channel Born-approximation calculations.