Collective properties of 48Cr at high spin

High-spin states of the nucleus 48Cr have been studied via particle-γ-γ spectroscopy, following the 28Si(28Si,2α) reaction. A 44-element particle-detector array was used to isolate 48Cr residues and to reduce γ-ray Doppler broadening. The collective band built upon the ground state has now been firmly established to spin 16+, the highest possible in the isolated f72 shell, and lifetimes of the four highest states have been measured from Doppler shifts. Although some of the ground-state band properties are well reproduced by recent fp-shell model calculations, a sharp reduction in E2 transition rates at the backbend is not.