The application of the iterative R-matrix method to the ¹²C(p,p)¹²C reaction

The iterative R-matrix (IRM) method has been applied to the study of the ¹²C(p,p)¹²C reaction below 8 MeV using a collective rotational model for the target nucleus. The predictions of the method employing the natural boundary conditions and the lowest four basis states per channel have been found to be substantially better than the corresponding standard R-matrix calculations with the boundary condition parameter b_c=0 and the channel radius a_c=6.0 fm in all channels. The results for the phase-shifts and inelasticity factors for J^pi =¹/₂⁺, ³/₂⁺ and ⁵/₂⁺ obtained using the IRM method are generally in good agreement with the equivalent coupled-channels calculations, and hence with the corresponding phase-shift analyses of the experimental data in the energy region of interest.