ISOSPIN CHARACTER OF TRANSITIONS TO BOUND-STATES IN PB-204,PB-206,PB-208 USING INELASTIC-SCATTERING OF O-17 IONS

We have measured the scattering of 375-MeV O-17 ions by isotopes of Pb-204, Pb-206, Pb-208 to investigate the isospin character of transitions to low-lying 2+ and 3- states. The data were analyzed using the deformed optical potential model. The 2+ collective strength, which is concentrated in a single state at 4.085 MeV in Pb-208, is observed to fragment in both Pb-204 and Pb-206. The differential cross sections for excitation of the collective 2+ and 3- states are well reproduced by model calculations in which it is assumed that M(n)/M(p) = N/Z (i.e., isoscalar character). Angular distributions for the lowest-lying 2+ states in Pb-203, Pb-206 are significantly different from those for the higher-lying collective 2+ states, and can be reproduced with M(n)/M(p) almost-equal-to 2.5. The data are compared with random-phase-approximation calculations including pairing, and good agreement is found within estimated uncertainties.