Coulomb breakup of and the flux of neutrinos from the SunB. Davids1, 2, S.M. Austin1, 2, D. Bazin1, H. Esbensen3, B.M. Sherrill1, 2, I.J. Thompson4 and J.A. Tostevin4
1 National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824, USA
2 Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA
3 Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA
4 Department of Physics, School of Physics and Chemistry, University of Surrey, Guildford, UK
(Received: 21 March 2002 / Published online: 31 October 2002)
A kinematically complete measurement was made of the Coulomb dissociation of 8B 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 7Be(p, ) 8B 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 = 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 7Be(p, ) 8B 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 8B solar neutrinos, which is also given.
25.70.De - Coulomb excitation.
26.20.+f - Hydrostatic stellar nucleosynthesis.
26.65.+t - Solar neutrinos.
© Società Italiana di Fisica, Springer-Verlag 2002