First-order eikonal model analysis for 12C+12C and 16O+16O elastic scatterings and the tangential velocity effect

We present the first-order eikonal model based on an approximated hyperbolic trajectory with tangential velocity at the distance of closest approach, which has been applied to elastic scatterings of the C-12+C-12 system at E-lab=360 and 1016 MeV and of the O-16+O-16 system at E-lab=480 and 1120 MeV. The calculated results, taking into account the tangential velocity effect, show better agreements with the observed data than the asymptotic velocity results. The oscillatory structures observed in the angular distribution could be explained due to interference between the near- and the far-side amplitudes. We have found that the first-order eikonal correction with tangential velocity at the distance of closest approach is important for understanding elastic scatterings of the C-12+C-12 and the O-16+O-16 systems.