Spectral structure of the pygmy dipole resonance.
High-sensitivity studies of E1 and M1 transitions observed in the reaction 138Ba(gamma,gamma{'}) at energies below the one-neutron separation energy have been performed using the nearly monoenergetic and 100% linearly polarized photon beams of the HIgammaS 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.
Tonchev
A P
AP
Duke University, Durham, North Carolina 27708-0308, USA.
Hammond
S L
SL
Kelley
J H
JH
Kwan
E
E
Lenske
H
H
Rusev
G
G
Tornow
W
W
Tsoneva
N
N