Decay angular correlations and spectroscopy for 10Be*→4 He+6He -: art. no. 044604

The Li(Li-7, Be-10* --> He-4 + He-6) reactions have been studied at bombarding energies of 34 and 50.9 MeV, For Be-10* production near 0 degrees, decay angular correlations are used to determine the previously unknown spin values and more accurate excitation energies of J = 2 at E-x = 9.56 MeV and J = 3 at E-x = 10.15 MeV. New excited states are proposed at higher excitations. A triaxial rotor model calculation and other collective rotation proposals all require a J = 4 state in the vicinity of 9 to 11 MeV, which has not been found. Angular correlation methods more general than have been used in the recent past are discussed.