Statistical properties of the well deformed ${}^{153,155}$Sm nuclei and the scissors resonance

Abstract

The Nuclear Level Densities (NLDs) and the $\gamma$-ray Strength Functions ($\gamma$SFs) of ${}^{153,155}$Sm have been extracted from (d,p$\gamma$) coincidences using the Oslo method. The experimental NLD of ${}^{153}$Sm is higher than the NLD of ${}^{155}$Sm, in accordance with microscopic calculations. The $\gamma$SFs of ${}^{153,155}$Sm are in fair agreement with QRPA calculations based on the D1M Gogny interaction. An enhancement is observed in the $\gamma$SF for both ${}^{153,155}$Sm 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 ${\mu }_N^2$ for ${}^{153}$Sm and ${}^{155}$Sm, respectively. The strength of the SR for ${}^{155}$Sm is comparable to those for deformed even-even Sm isotopes from nuclear resonance fluorescence measurements, while that of ${}^{153}$Sm is lower than expected.

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Cited by in corpus (2)

• Strong enhancement of level densities in the crossover from spherical to deformed neodymium isotopes
• Experimentally constrained ${}^{165,166}\text{Ho}(n,\gamma )$ rates and implications for the $s$ process