R-MATRIX AND K-MATRIX ANALYSIS OF ELASTIC ALPHA-ALPHA SCATTERING

The R- and K-matrix parametrizations are analyzed and compared for the elastic alpha-alpha scattering at center-of-mass energies below 40 Me V. The two parametrizations differ in their definitions of the resonan ce energy which can lead to quite different results. The physical valu es of the best-fit parameters are compared with those computed for a p otential model. The existence of a broad resonance near 9 MeV is not s upported by the data or by the potential model. We discuss the positiv e and negative aspects for both parametrizations. (C) 1998 Published b y Elsevier Science B.V.