Measurement of d + ~7Be Cross Sections for Big-Bang Nucleosynthesis

摘要

The cross sections of nuclear reactions between the radioisotope Be-7 and deuterium, a possible mechanism of reducing the production of mass-7 nuclides in big-bang nucleosynthesis, were measured at center-of-mass energies between 0.2 and 1.5 MeV. The measured cross sections are dominated by the (d, alpha) reaction channel, towards which prior experiments were mostly insensitive. A new resonance at 0.36(5) MeV with a strength of omega gamma = 1.7(5) keV was observed inside the relevant Gamow window. Calculations of nucleosynthesis outcomes based on the experimental cross section show that the resonance reduces the predicted abundance of primordial Li-7, but not sufficiently to solve the primordial lithium problem.