New measurement and analysis of the ⁷Be(p, γ)⁸ B cross section

Cross sections for the 7Be(p, γ)8B reaction have been measured for Ec.m. = 0.35 − 1.4MeV using radioactive 7Be targets. Two independent measurements carried out with different beam conditions, different targets, and detectors are in excellent agreement. A statistical comparison of these measurements with previous results leads to a restricted set of consistent data. The deduced zero-energy S factor S(0) is found to be 15%-20% smaller than the previously recommended value. This implies a 8B solar neutrino flux lower than previously predicted in various standard solar models. © 1998 American Physical Society.