Treiman-Yang criterion as a test of the pole approximation in theBe9(He3,αα)He4reaction

The ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$(${}_{}{}^3{}_{}{}^{}\mathrm{He}$,$\alpha \alpha$)${}_{}{}^4{}_{}{}^{}\mathrm{He}$ reaction has been studied at low incident energy to test the predictions of the pole approximation. Treiman-Yang distributions have been deduced from the measured differential cross sections for a wide range of the Treiman-Yang angle and of the spectator momentum. The data are consistent with the isotropic distribution predicted by the pole mechanism.