Coulomb excitation of 115Sn

Coulomb excitation of the nucleus ¹¹⁵Sn was studied with beams of ⁴He and ¹⁶O. Level energies, spins, mean-lives and B(E2) and B(M1) transition probabilities were obtained. Spin $\text{3}\text{2}$⁺ states were observed at 497.35 and 1280.08 keV and spin $\text{5}\text{2}$⁺ states were observed at 986.54 and 1416.78 keV. A state of 612.79 keV was observed to be indirectly excited by decay of the Coulomb excited states. Eleven B(E2) values and nine B(M1) values were obtained for the transitions between the low-lying states. In contrast to previous particle transfer results which suggested a clear distinction between shell-model and collective $\text{3}\text{2}$⁺ and $\text{5}\text{2}$⁺ states, our results suggest the collective strength is shared by the two $\text{3}\text{2}$⁺ and two $\text{5}\text{2}$⁺ states.     

Two-step mechanism in the 22Ne(p,t) reaction

The forward-angle differential cross sections have been measured for the ²²Ne(p,t) reaction leading to the 4.97 MeV, 2^? state in ²⁰Ne. Comparison of the data with the results of calculations shows that the two-step mechanism responsible for exciting this state is (p-p′-t) rather than (p-d-t).