Isovector Quadrupole Excitations in the Valence Shell studied in Projectile Coulomb Excitation Original Research Article

One-phonon states of heavy vibrational nuclei with mixed proton-neutron symmetry have recently been made accessible by the technique of projectile Coulomb excitation. Gamma-rays following Coulomb excitation of the nuclides 136,138Ce and 134Xe have been measured with the Gammasphere-array run in singles-mode. M1, E2, and E3 transition matrix elements from low-spin states were measured relative to the known View the MathML source values. The View the MathML source strength distributions up to about 2.7 MeV serve for identifying the main fragment of the View the MathML source one-quadrupole phonon mixed-symmetry state. The data are presented and their significance is discussed.