Coulomb-nuclear interference measurements of hexadecapole deformations in168Yb and178,180Hf

Abstract
Coulomb-nuclear interference studies of 168Yb and 178,180Hf have been carried out with alpha particles from the Pittsburgh tandem. From coupled channel fits to the data at 18 MeV for 168Yb and 19.5 MeV for 178,180Hf, beta 4c values of -0.030(20), -0.166(18), and -0.180(6) were obtained, respectively. These data agree with the positive M04 value from sub-Coulomb studies of 168Yb but with the large negative M04 values from sub-Coulomb studies of 178,180Hf.