Optical potential ambiguities and 16O+16O at 350 MeV

The elastic scattering of 16O+16O at 350 MeV has been reanalyzed using more general optical model potential shapes in an attempt to resolve the ambiguity over the order of rainbow seen in the angular distribution. We conclude that probably it is the primary rainbow, determining the real potential to have a volume integral Jv≈295±MeV fm3. However, the use of real potentials with non-monotonic shapes defined by splines does still allow the possibility of it being the secondary rainbow generated by a deeper potential. In addition, the use of splines introduces a more shallow potential which also implies observation of the primary rainbow.