Orbital magnetic dipole mode in deformed clusters: A fully microscopic analysis

The orbital M1 collective mode predicted for deformed clusters in a schemat ic model is studied in a self-consistent random-phase-approximation approac h which fully exploits the shell structure of the clusters. The microscopic mechanism of the excitation is clarified and the close correlation with th e E2 mode established. The study shows that the M1 strength of the mode is fragmented over a large energy interval. In spite of that, the fraction rem aining at low energy, well below the overwhelming dipole plasmon resonance, is comparable to the strength predicted in the schematic model. The import ance of this result in view of future experiments is stressed.