Reconciling Coulomb breakup and neutron radiative capture
AbstractThe Coulomb-breakup method to extract the cross section for neutron radiative capture at astrophysical energies is analyzed in detail. In particular, its sensitivity to the description of the neutron-core continuum is ascertained. We consider the case of C14(n,γ)C15 for which both the radiative capture at low energy and the Coulomb breakup of C15 into C14+n on Pb at 68 MeV/nucleon have been measured with accuracy. We confirm the direct proportionality of the cross section for both reactions to the square of the asymptotic normalization constant of C15 observed by Summers and Nunes [Phys. Rev. C 78, 011601(R) (2008)10.1103/PhysRevC.78.011601], but we also show that the C14-n continuum plays a significant role in the calculations. Fortunately, the method proposed by Summers and Nunes can be improved to absorb that continuum dependence. We show that a more precise radiative-capture cross section can be extracted selecting the breakup data at forward angles and low C14-n relative energies.