Investigation of the isospin-forbidden reaction6Li(6Li,d 2)10 B 0+,1

Angular distributions of the isospin-forbidden reaction⁶Li(⁶Li, d₂)¹⁰ B _0+,1 were measured at six beam energies in the range from 3 to 8 MeV. The contribution of two-step transfer mechanism to the reaction under consideration was found to be negligible. Hauser-Feshbach model cross sections, obtained with parameters derived from a previous analysis of isospin-allowed reactions in the⁶Li +⁶Li system are consistent with the data, provided a 2% reduction factor reflecting isospin mixing of compound nucleus levels. From this factor an isospin-breaking matrix element of H _c ^{2 1/2}13 keV was deduced. The presence of one broad or several resonances with (J ^P ,T)=(1^–, 1) or (2^–,1) concentrated at an excitation energy of about 30.3 MeV in¹²C seems to be responsible for the observed shape of angular distributions and their energy dependence.This work was supported by Deutsche Forschungsgesellschaft under contact No. Fr575/2-1,2.