Using the ${}^{40}\mathrm{Ca}$(${}^3\mathrm{He}$,$p$) reaction at ${\text{E}}_{{}^3\mathrm{He}}=9$ MeV and the multidetector array HORUS, angular correlations of coincident pairs of γ transitions in the odd-odd $N=Z$ nucleus ${}^{42}\mathrm{Sc}$ have been measured at the FN tandem Van de Graaff accelerator of the University of Cologne. The analysis of the data allowed nine new spin assignments and the determination of a series of new multipole mixing ratios. In particular, the spin and parity of the $5^{+}$ and $7^{+}$ levels belonging to the lowest $T=0\pi f_{7/2}\nu f_{7/2}$ multiplet have been determined and the ($6^{+}$) level from the $T=1$ multiplet has been tentatively assigned. In this way, all $T=1$ states up to an excitation energy of 3.2 MeV now have known spins as well as the lowest $T=0$ quadruplet ($J^{\pi }=1^{+},3^{+},5^{+},7^{+}$) and many other $T=0$ states of unknown structure. The comparison with shell-model calculations reveals that a breaking of the ${}^{40}\mathrm{Ca}$ core has to be invoked to describe the level structure of ${}^{42}\mathrm{Sc}$.

• Received 13 February 2007

DOI:https://doi.org/10.1103/PhysRevC.75.064321