Vanishing Spin Alignment: Experimental Indication Of A Triaxial Si-28+Si-28 Nuclear Molecule

Fragment-fragment-gamma coincidences have been measured for Si-28+Si-28 at an energy corresponding to the population of a conjectured resonance in Ni-56. Fragment angular distributions as well as gamma-ray angular correlations indicate that the spin orientations of the outgoing fragments are perpendicular to the orbital angular momentum. This differs from the Mg-24+Mg-24 and the C-12+C-12 resonances, and suggests two oblate Si-28 nuclei interacting in an equator-to-equator molecular configuration. [S0556-2813(99)50610-9].