Rotational band structure inPr133

The level structure of the odd proton nucleus ${}_{}{}^{133}{}_{}{}^{}\mathrm{Pr}$ has been investigated. Excited states up to spin frac452 have been observed. The yrast band, built on a decoupled $h_{\frac{11}{2}}$ proton, shows an up-bend at $\hslash \omega =0.43\mathrm{}$ MeV when two additional $h_{\frac{11}{2}}$ protons align. Two positive parity side bands, based on the $g_{\frac{7}{2}}{\frac{5}{2}}^{+}\mathrm{}\left[413\right]\mathrm{}$ proton configuration, are established with opposite signature. Both show a band crossing at $\hslash {\omega }_c=0.27\mathrm{}$ MeV with a gain in $\mathrm{alignment}\approx 8\hslash$, when two $h_{\frac{11}{2}}$ protons decouple. This low crossing frequency is partly explained by a reduction in the proton pairing gap caused by the $g_{\frac{7}{2}}$ proton.