Electromagnetic dissociation of B-8 and the astrophysical S factor for Be-7(p, gamma)B-8

We present S factor data obtained from the Coulomb dissociation of 83 MeV/nucleon B-8, and analyze Be-7 longitudinal momentum distributions measured at 44 and 81 MeV/nucleon using a potential model, first-order perturbation theory, and dynamical solution of the time-dependent Schrodinger equation. Comparing our results with independent continuum-discretized coupled channels calculations, we study the reaction model and beam energy dependence of the E2 contribution to the dissociation cross section. By fitting radiative capture and Coulomb breakup data taken below relative energies of 400 keV with potential models constrained by Li-7+n and Be-7+p elastic scattering data, we examine the mutual consistency of recent S-17 measurements and obtain a recommended value for S-17(0) of 18.6+/-0.4 (experimental) +/-1.1 (extrapolation) eV b (1sigma). This result is in good agreement with recent experimental determinations of the asymptotic normalization coefficient of the valence proton wave function in B-8.