A 20MeV (p,d) study of nuclear structure in the even and odd tin isotopes

The even and odd tin isotopes have been studied by 20 MeV (p,d) reactions. States strongly populated in the odd isotopes are due to the valence neutron shells and extend up to only 2 MeV of excitation energy; 'deep hole' states were not identified. The occupation probabilities extracted from finite-range distorted-wave-Born-approximation calculations generally agree well with the predictions of the BCS theory of superconducting nuclei, particularly with the calculations of Clement and Baranger. In the even tin isotopes, strongly populated states are characterized predominantly by L=2 transfers extending up to 4 MeV excitation energy. The experimental spectroscopic factors are compared with the BCS calculated values of Clement and Baranger, Alzetta and Sawicki, and Van Gunsteren; relatively good agreement is obtained for L=2 transitions, but not for L=0 transitions. A considerable fraction of the sum rule L=2 strength in 118Sn is missing in the 119Sn(p,d)118Sn experimental spectrum; in like manner, no 4+ strength could be identified in either 114Sn or 118Sn