12C(d, α 2) 10B and isospin violating two-step reactions

Abstract

A model-independent S-matrix analysis for the isospin violating 12C(d, α 2) 10B( E x = 1.74 MeV) reaction was performed and the results compared to a recently published two-step coupled channels calculation. There are multiple solutions to the S-matrix fits. but it is found that none of the possible solutions are compatible with the partial-wave decomposition based upon the two-step mechanism. The data are satisfactorily fitted with a sum of Breit-Wigner resonances. When a non-resonant background is included in the calculation the result indicates that the magnitude of such a contribution is less than 2 % of the measured total cross section at E d = 15 MeV and is consistent with zero. The reaction is therefore interpreted to proceed almost entirely through the compound nucleus.