S17(0)Determined from the Coulomb Breakup of 83 MeV/NucleonB8

A kinematically complete measurement was made of the Coulomb dissociation of ${}^{8}\mathrm{B}$ 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 ${}^{7}\mathrm{Be}(p,\ensuremath{\gamma}{)}^{8}\mathrm{B}$ reaction. A first-order perturbation theory analysis 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 ${E}_{\mathrm{rel}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}130$ to 400 keV, we find ${S}_{17}(0){\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}17.8}_{\ensuremath{-}1.2}^{+1.4}\phantom{\rule{0ex}{0ex}}\mathrm{eV}\mathrm{b}$.