Vertex function and coupling constant for the virtual decay of 7Li

The alpha-triton relative wave function with various nucleon exchange contributions and their asymptotic normalization are considered in the framework of the generator coordinate method (GCM). The asymptotic normalization of relative wave function provide the estimate of the coupling constant. The relative wave function is also used to obtain 7Li-α-t vertex function in the virtual decay of 7Li. The extrapolation of vertex function for negative values of q2 up to the alpha-triton pole provide the vertex constant, which is compared with the experimentally determined estimates 0.67 FM and 0.72 FM. Our calculated value is 0.0656 FM which is in close agreement with the above estimates. (author)