Coulomb breakup of 6Li into α plus d in the field of a 208Pb ion

The triple differential cross section of the Pb-208(Li-6, alpha d)Pb-208 quasielastic breakup is calculated at a collision energy of 156 MeV and a scattering angle range of 2 degrees-6 degrees. We fit the parameters of the Woods-Saxon potential using the experimental alpha-d phase shifts for different states to describe the relative motion of the alpha particle and deuteron. To check the validity of the two particle approach for the alpha-d system, we apply a potential model to describe the H-2(alpha,gamma)Li-6 radiative capture. We calculate the Coulomb breakup using the semiclassical method while an estimation of the nuclear breakup is made on the basis of the diffraction theory. A comparison of our calculation with the experimental data of Kiener et al. [Phys. Rev. C 44, 2195 (1991)] gives evidence for the dominance of the Coulomb dissociation mechanism and the contribution of nuclear distortion, but is essentially smaller than the value reported by Hammache et al. [Phys. Rev. C 82, 065803 (2010)]. The results of our calculation for the triple cross sections (contributed by the Coulomb and nuclear mechanisms) of the Li-6 breakup hint toward a forward-backward asymmetry in the relative direction of the alpha particle and deuteron emission, especially at smaller scattering angles, in the Li-6 center-of-mass (c. m.) system.