K. Govaert et al., OBSERVATION OF A 1- 2 PHONON 2-TIMES 3- EXCITATION IN SN-116 AND SN-124( CIRCLE), Physics letters. Section B, 335(2), 1994, pp. 113-118
In nuclear resonance fluorescence experiments with unpolarized and lin
early polarized bremsstrahlung we have observed for the first time ver
y strong electric dipole transitions at about 3.5 MeV in the spherical
, semi magic Sn-116 and 124Sn nuclei. These transitions can be attribu
ted to possible two phonon 2+ X 3- excitations. The measured transitio
n strengths are compared to the results of a QRPA calculation.