A comparison of K- and R-matrix parameterizations of s-wave O-16+p elastic scattering

Values for the reduced proton width of the 1/2(+) bound state of F-17 are extracted using K- and R-matrix fits to s-wave O-16 +p phase shifts. The reduced proton width is also calculated using a potential model which reproduces the elastic scattering data and also the O-16(p,gamma) cross section into the 1/2(+) state. The fitted K-matrix reduced proton width is inconsistent with the R-matrix value and also the potential model calculation. Investigations using the potential model reveal that the likely cause of the discrepancy is the complicated nature of the K-matrix background. We find that the background cannot be adequately represented by the sum of real-energy pole and a constant.