Lifetime measurements inSm135: Large deformation in theN=6 intruder band and evidence for quenched proton pairing

Abstract

The quadrupole moment of the highly deformed band built upon the ${\mathit{i}}_{13/2}$ neutron intruder orbital in ${}_{}{}^{135}{}_{}{}^{}\mathrm{Sm}$ has been measured, using the Doppler shift attenuation method and Braune stopping powers, to be 7.0±0.7 e b. These data provide strong evidence that this high-j, N=6 intruder orbital is responsible for the highly deformed states seen in this region. The result is compared to total Routhian surface calculations. A possible explanation for the observed anomalous behavior of the ${\mathit{J}}^{\mathrm{}\left(2\right)\mathrm{}}$ moment of inertia in this nucleus is discussed in terms of quenched static proton pair correlations.