Stellar and Primordial Nucleosynthesis of {sup 7}Be: Measurement of {sup 3}He({alpha},{gamma}){sup 7}Be

The {sup 3}He({alpha},{gamma}){sup 7}Be reaction presently represents the largest nuclear uncertainty in the predicted solar neutrino flux and has important implications on the big bang nucleosynthesis, i.e., the production of primordial {sup 7}Li. We present here the results of an experiment using the recoil separator ERNA (European Recoil separator for Nuclear Astrophysics) to detect directly the {sup 7}Be ejectiles. In addition, off-beam activation and coincidence {gamma}-ray measurements were performed at selected energies. At energies above 1 MeV a large discrepancy compared to previous results is observed both in the absolute value and in the energy dependence of the cross section. Based on the available data and models, a robust estimate of the cross section at the astrophysical relevant energies is proposed.