Study of the 3He(4He,γ)7Be and 3H(4He,γ)7Li Reactions in an Extended Two-Cluster Model

 The 3He(4He, γ)7Be and 3H(4He, γ)7Li reactions are studied in an extended two-cluster model which contains α + h/t and 6Li + p/n clusterizations. We show that the inclusion of the 6Li + p/n channels can significantly change the zero-energy reaction cross sections, S(0), and other properties of the 7Be and 7Li nuclei, like the quadrupole moments Q. However, the results agree with the known correlation trend between S(0) and Q. Moreover, we demonstrate that the value of the zero-energy derivatives of the astrophysical S-factors are more uncertain than currently believed.