Systematics of low-lying electric dipole excitations in theA130–200 mass region

Abstract
The data from numerous high resolution photon scattering experiments allow an extensive survey of the lowest electric dipole excitations in the A130–200 mass region. In this mass region one can find spherical as well as transitional and strongly quadrupole deformed nuclei. The measured absolute E1 strengths are typically of the order of several milli Weisskopf units and exhibit in general a smooth variation with mass number.