Coulomb breakup of 8 B and the flux of 8 B neutrinos from the

A kinematically complete measurement was made of the Coulomb dissociation of B nuclei on a Pb target at 83 MeV/nucleon. The cross-section was measured at low relative energies in order to infer the astrophysical S-factor for the Be(p,γ)B reaction. A first-order perturbation theory analysis of the reaction dynamics including E1, E2, and M1 transitions was employed to extract the E1 strength relevant to neutrino-producing reactions in the solar interior. By fitting the measured cross-section from Erel = 130 keV to 400 keV, we find S17(0) = 17.8 +1.4 −1.2 eV b. Semiclassical 1st-order perturbation theory and fully quantum-mechanical continuum-discretized coupled-channels analyses yield nearly identical results for the E1 strength relevant to solar-neutrino flux calculations, suggesting that theoretical reaction mechanism uncertainties need not limit the precision of Coulomb-breakup determinations of the Be(p,γ)B S-factor. A recommended value of S17(0) based on a weighted average of this and other measurements is presented. This recommendation implies a revised value for the theoretical flux of B solar neutrinos, which is also given. PACS. 25.70.De Coulomb excitation – 26.20.+f Hydrostatic stellar nucleosynthesis – 26.65.+t Solar