Search for shape isomers in /sup 56/Ni

An excitation function for the 40Ca(/sup 16/O,/sup 28/Si/sup */)/sup 28/Si/sup */ reaction has been measured between 74.925 less than or equal to E/sub lab/ less than or equal to 77.25 MeV in 75-keV steps for 30/sup 0/ less than or equal to theta/sub lab/ less than or equal to 60/sup 0/. $Q: -value and angular distributions were measured at each beam energy. Intermediate width (GAMMAapprox. =200 keV) structures are present in the excitation function at the 3--5% level of the cross section. An analysis of the present excitation function, together with one previously obtained for the inclusive elastic and inelastic /sup 28/Si+/sup 28/Si scattering yields, indicates that the structures in the two excitation functions are correlated at an 80% confidence level. This suggests that the process responsible for the resonances is of compound-nuclear origin.