Distortion Effects ind+αSystem

The deuteron specific distortion effect in the $d+\alpha$ problem is considered with a microscopic procedure. This procedure consists in the addition of square-integrable or distortion functions into the usual no-distortion resonating-group wave function. The result shows that with the consideration of this effect, a nucleon-nucleon potential which fits the low-energy two-nucleon scattering data and which yields a satisfactory agreement with the empirical $\alpha +\alpha$ phase shifts can be used to describe quite well the $d+\alpha$ experimental data. Also, it is shown that the specific distortion effect has an odd-even character; it has significant effects in even-$l$ states, but not in odd-$l$ states. Resonance structures are found in the partial-wave scattering amplitudes. These structures arise as a consequence of the coupling of the compound-nucleus states with the elastic scattering channel.