The excited states of ${}^{93}\mathrm{Zr}$ have been investigated using the heavy-ion fusion-evaporation reaction ${}^{82}\mathrm{Se}({}^{18}\mathrm{O},\alpha 3n){}^{93}\mathrm{Zr}$ at the beam energies of 82 and 88 MeV. Particle-$\gamma \text{−}\gamma$ and $\gamma \text{−}\gamma$ coincidence measurements using CsI and HPGe arrays are employed to gain selectivity to Zr isotopic products. The level scheme of ${}^{93}\mathrm{Zr}$ was extended up to $E\approx 12.5\mathrm{Mev}$ and $I^{\pi }=(47/2^{-})$ with twenty-six new $\gamma$-ray transitions. The observation of $\gamma$ rays with $\approx 2\mathrm{Mev}$ and the associated fragmentation of the $\gamma$-ray flux into many competing pathways provide a clear experimental signature for the breaking core. Level structures in ${}^{93}\mathrm{Zr}$ were interpreted in the framework of the spherical shell model in a model space including the proton orbitals ($1f_{5/2}, 2p_{3/2}, 2p_{1/2}, 1g_{9/2}$) and neutron orbits ($1g_{9/2}, 1g_{7/2}, 2d_{5/2}, 1h_{11/2}$). A possible reduction of the $Z=38$ subshell spacing gap in ${}^{93}\mathrm{Zr}$ is discussed.

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• Fusion evaporation reactions
• High spin states
• Nuclear spin & parity
• Nuclear structure & decays
• Shell model
• 90 ≤ A ≤ 149
• Nucleon spin structure
• Spectrometers & spectroscopic techniques