Search for a resonant enhancement of the 7Be + d reaction and primordial 7Li abundances

Big Bang nucleosynthesis calculations, constrained by the Wilkinson Microwave Anisotropy Probe results, produce ⁷Li abundances almost a factor of four larger than those extrapolated from observations. Since primordial ⁷Li is believed to be mostly produced by the beta decay of ⁷Be, one proposed solution to this discrepancy is a resonant enhancement of the ⁷Be(d,p)2α reaction rate through the 5/2⁺ 16.7-MeV state in ⁹B. The ²H(⁷Be,d)⁷Be reaction was used to search for such a resonance; none was observed. An upper limit on the width of the proposed resonance was deduced.