Statistical properties of the well deformed 153,155Sm nuclei and the scissors resonance

The nuclear level densities (NLDs) and the gamma-ray strength functions (gamma SFs) of Sm-153,Sm-155 have been extracted from (d, p gamma) coincidences using the Oslo method. The experimental NLD of Sm-153 is higher than the NLD of Sm-155, in accordance with microscopic calculations. The gamma SFs of Sm-153,Sm-155 are in fair agreement with QRPA calculations based on the D1M Gogny interaction. An enhancement is observed in the. SF for both Sm-153,Sm-155 nuclei around 3 MeV in excitation energy and is attributed to the M1 scissors resonance (SR). Their integrated strengths were found to be in the range 1.3-2.1 and 4.4-6.4 mu(2)(N) for Sm-153 and Sm-155, respectively. The strength of the SR for Sm-155 is comparable to those for deformed even-even Sm isotopes from nuclear resonance fluorescence measurements, while that of Sm-153 is lower than expected.

Automated summary

The nuclear level densities and gamma-ray strength functions of Sm-153, Sm-155 were extracted using the Oslo method, showing agreement with microscopic calculations and QRPA calculations. An enhancement in the gamma SFs around 3 MeV in excitation energy was attributed to the M1 scissors resonance in both nuclei.