16O Coulomb dissociation: towards a new means to determine the 12C+α fusion rate in stars

A feasibility study was made of an important aspect of the Coulomb-dissociation method, which has been proposed for the determination of the rate of the astrophysically important 12C(α, γ)16O reaction. A crucial aspect is the disentanglement of nuclear and Coulomb interactions on one hand and the separation of dipole and quadrupole contributions on the other. As a first step the resonant breakup via two well-known 2+ states of 16O was measured. The differential cross section of 208Pb(16O, 16O*)208Pb and the angular correlations of the fragments 12C and α in the center of mass were measured and compared to theoretical predictions calculated in DWBA and the coupled-channel method. The best agreement was found for the state at 11.52 MeV associated to a one-step excitation from the ground state, while the 9.84 MeV requires coupling to the first-excited 2+ state and is not well described.