Capture rate of the 7Li(n, γ)8Li reaction by prompt γ-ray detection

The reaction 7Li(n, γ)8Li is a trigger reaction which bridges the instability gap at mass 8 while producing heavy elements during the rapid process of nucleosynthesis. The reaction rate was remeasured at the most probable neutron energy of 30 keV by detecting prompt γ-rays from a captured state; 39.3 ± 6.0 μb was obtained. This value is two-times larger than that recently measured and agrees with the estimated value from the thermal neutron capture cross section by using the 1/v law. The result is discussed in terms of both nucleosynthesis and the solar neutrino problem. (author)