Nuclear resonance fluorescence in 142Nd

The resonant scattering of electron bremsstrahlung by an enriched sample of 142Nd has been studied for photon energies of up to 5 MeV. It provides estimates of the radiative widths for 13 levels. Based on the relative yields at scattering angles of 960 and 1260, unambiguous spin assignments were made to 6 of these levels. Where feasible, the yield measurements were supplemented by self-absorption data and by linear polarization studies. For the strongest excitation, at 3.425 MeV, the resonance fluorescence experiments led to its identification as a 1- state with a radiative width GAMMA0 = 370 +- 45 meV. The corresponding E1 strength is comparable to the E1 strengths measured in other even-even N = 82 nuclei for the 1- member of the quintuplet arising from the coupling of the lowest octupole vibration to the 2+1 level. The sum of the excitation energies of the 2+1 state and the 3-1 state in 142Nd is consistent with such an interpretation of the 3.425-MeV level