By a realistic dynamical microscopic reaction approach to ^He we reproduce the empirical positions of the two 5-matrix poles associated with the | resonance, and unambiguously prove that it arises from the t-\-d channel. The picture is not coherent though, unless the presently adopted a-\-n phase shift, extracted partly from a-\-p scattering data, is assumed to be incorrect. It is pointed out that the analog resonance in ^Li behaves very differently because the shadow pole is located on another Riemann sheet.

Cross sections have been measured for the quasielastic ^Liie.e'p) reaction in the missing-energy region beyond the t +d threshold, which is dominated by the j^ resonance. The data are compared with distorted-wave impulse-approximation calculations, which involve nuclear overlap functions derived from a cluster-distortion model extended to the continuum. The measured recoil-momentum dependence of the T^ resonance can only be reproduced if an anomalous longitudinal-transverse ratio is taken into account.