Resolution of a long-standing discrepancy in the 17O+12C fusion excitation function.

There has been a long-standing discrepancy between existing measurements of the total fusion cross section for the 17 O + 12 C system at E c. m. ∼ 14 MeV. In order to resolve this inconsistency, the cross section was measured in two overlapping energy ranges using an 17 O beam and the Encore active target detector at Florida State University. Encore is a self-normalizing detector that measures a large portion of the fusion excitation function with a single beam energy. It also provides full angular coverage of the measured evaporation residues, thus ensuring a model independent measurement of the total fusion cross section. The data reported here show an oscillatory structure not previously observed in this system and agree with all previously reported measurements, resolving the long-standing discrepancy. Coupled reaction channels calculations reproduce the data except in the region of the the oscillation, which matches a similar structure seen in the 16 O + 12 C total fusion excitation function. [ABSTRACT FROM AUTHOR]