Speaker
Description
Electromagnetic excitations (primarily M1 and E2) of heavy deformed nuclei, such as $^{154}$Sm, $^{166}$Er, etc., with excitation energies $E_x=2-4$ MeV will be discussed in terms of the most advanced Monte Carlo Shell Model (MCSM) calculations. For M1 excitations, the recent MCSM result indicates M1 spectrum very close to experimental ones, but we also see strong spin contributions. Such calculations can be extended to other nuclei. For E2 excitations, the triaxiality in the ground state has been clarified in a recent theoretical work, and this triaxiality induces an associated "gamma" band at high excitation energy. For instance, this results in a $2^+$ state of $E_x=2.5-3$ MeV with $B(E2; 0^+_1 \to 2^+)\sim 400~e^2 fm^4$.
We can survey this type of E2 excitation, which is stronger than usual E2 excitations to states in this energy range. Thus, the recent advancement of the MCSM calculations brings about new features to be explored by photon and/or electron scattering experiments.
