High spin resonances in "1"2C+"1"2C scattering

Recent measurements of the excitation function for the reaction "1"2C["1"2C,"1"2C(3_1"-)] "1"2C(3_1"-) from E_c_._m_. = 32 to 45 MeV revealed peaks at the centre-of mass energies E_c_._m_. = 32.5, 37.5 and 43 MeV. In the present study, detailed angular correlation measurements are performed suggesting that each of these energies correspond to a dominant angular momentum J=18, 20 and 22 (h/2#pi#) respectively. Theory predicts that there are two main configurations of "2"4Mg which can sustain a value of J#>=#16 (h/2#pi#). One is the six #alpha#-particle linear chain state, the other has a highly deformed "1"2C+"1"2C structure (F1). The mutual 3_1"- channel is considered to be associated with the Fl configuration in "2"4Mg, which according to theory, is able to sustain a maximum angular momentum value of J 22 (h/2#pi#). A further experiment was performed to extend the excitation function up to E_c_._m_.= 60 MeV to test for the termination of the mutual 3_1"- band of resonances. Other open channels, the most important of which is the "1"2C(4_1"+) single and mutual channels, were also investigated and an angular correlation measurement of a broad peak in the excitation function for the "1"2C["1"2C,"1"2C(4_1"+)]"1"2C_g_._s_. channel at E_c_._m_.= 44 MeV was performed. Using the same extensive data set, an investigation was also conducted to observe the "1"2C["1"2C,"1"6O*]"8Be channel. Reconstruction of a number of "1"6O states formed from a triplet of "8Be fragments have been observed at 28, 31.5, and 35.5 MeV respectively. Preliminary analysis would suggest that these states form a "1"6O(6"+, 8"+, 10"+) rotational band. However only spins for the 6"+ and 8"+ have been definitely determined in the present study. These states have been suggested by the author to be candidates for a four #alpha#-particle chain state. (author)Available from British Library Document Supply Centre-DSC:D213761 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo