Investigation of dipole excitations inCe142using resonant photon scattering

Experiments on multiphonon states with proton–neutron mixed symmetry in vibrational nuclei

“…were determined [36]. This finding has been interpreted [36,140] as a fragmentation of the 2 + 1,ms state over these two close-lying experimental 2 + 3,4 states. Two-phonon MS states of 142 Ce with positive parity have not been firmly identified up to now.…”

“…Data on R E1 have constrained the parameters of the effective quadrupole-octupole coupled E1 transition operator of the sd f -IBM-2 that make the predictions for E1 decay properties of other quadrupole-octupole coupled structures possible. Following those predictions a tentative assignment of quadrupole-octupole coupled MSS with negative parity has become possible for the first time [140]. …”

“…Two-phonon MS states of 142 Ce with positive parity have not been firmly identified up to now. A recent photon scattering experiment [140] identified 14 dipole excitations in the energy range from 2.1 to 3.9 MeV. Due to the lack of solid parity information for all of them but the lowest two below 2.4 MeV a more conclusive assignment of two-phonon 1 + ms states could not be made.…”

“…Due to the lack of solid parity information for all of them but the lowest two below 2.4 MeV a more conclusive assignment of two-phonon 1 + ms states could not be made. From the observed γ -ray decay branching ratios of these dipole excitations to the ground state and to the 2 + 1 , one J = 1 state could be identified [140] which can be considered as a promising candidate for being a first 1 − ms state resulting from the coupling of the 2 + 1,ms state to the 3 − 1 octupole vibration [62]. However, more data are needed for a more solid assignment.…”

Multiphonon states in56136Ba80

“…In the A ≈ 130 region, 2 + 1,ms states and the 1 + 2,ms member of the two-phonon MSS have been identified in 128 Xe [17,18], 126 Xe [18,19], 134 Ba [20][21][22], 136 Ba [23], and 142 Ce [24,25]. These MSS appear to be more fragmented than those observed in the N ≈ 50 region, and the splitting strength is generally attributed to mixing of the 2 + states.…”