Abstract:
High-sensitivity studies of E1 and M1 transitions observed in the reaction Ba-138((gamma) over right arrow, gamma') at energies below the one-neutron separation energy have been performed using the nearly monoenergetic and 100% linearly polarized photon beams of the HI (gamma) over right arrowS facility. The electric dipole character of the so-called "pygmy" dipole resonance was experimentally verified for excitations from 4.0 to 8.6 MeV. The fine structure of the M1 "spin-flip" mode was observed for the first time in N = 82 nuclei.
