High-spin states in odd-massSb113−119:ΔJ=1bands on92+proton-hole states

Properties of high-spin states in ${}_{}{}^{113,115,117,119}{}_{}{}^{}\mathrm{Sb}$ have been studied via the ${}_{}{}^A{}_{}{}^{}\mathrm{Cd}({}_{}{}^6{}_{}{}^{}\mathrm{Li},3n){}_{}{}^{A+3\mathrm{}}{}_{}{}^{}\mathrm{Sb}$ reactions. Using Ge(Li) and Si(Li) detectors, in-beam measurements of $\gamma$-ray excitation functions, $\gamma -\gamma$ coincidences, $\gamma$-ray angular distributions, and pulsed beam-$\gamma$ timing spectra were made to determine level energies, decay schemes, $\gamma$-ray multipolarities, $J^{\pi }$ assignments, isomeric lifetimes, and a $g$ factor. Systematic $\Delta J=1\mathrm{}$ bands built on low-lying $\frac{9}{2^{+}}$ proton-hole (2p-1h) states were observed in these nuclei. The bandheads that involve the excitation of a $1g_{\frac{9}{2}}$ proton across the $Z=50\mathrm{}$ shell achieve an energy minimum near the middle of the neutron shell. The observed properties of these bands are consistent with significant prolate deformations; the band spacings imply a deformation asymmetry of $\gamma =20\mathrm{}$ in a triaxial rotor model. In addition, single-particle and single-particle plus core-excitation states were observed in these Sb nuclei. Two isomers were identified, a $\frac{19}{2^{\mathrm{}(-)\mathrm{}}}$ state at 2796 keV in ${}_{}{}^{115}{}_{}{}^{}\mathrm{Sb}$ ($\tau =230\mathrm{}\pm 4$ ns and $g=+0.290\mathrm{}\pm 0.005$) and a ($\frac{27}{2^{+}}$) state in ${}_{}{}^{119}{}_{}{}^{}\mathrm{Sb}$ ($\tau =1.23\mathrm{}\pm 0.13$ s).