First determination of the 8Li valence neutron asymptotic normalization coefficient using the 7Li( 8Li,7Li)8Li reaction.

摘要

Solar neutrino experiments have often been plagued with large uncertainties. With the recent results from the Borexino Collaboration, for the first time the total uncertainty in the 7Be solar neutrino flux measurement is smaller than the uncertainty of standard solar model (SSM) predictions.;Improvement in neutrino experiments must be followed by refinements to the SSM; to do so requires reduced uncertainties on the parameters used in SSM calculations. One such value is the astrophysical S-factor describing the 7Be(p,gamma)8B reaction, S17(0).;We report here a determination of the asymptotic normalization coefficient (ANC) of the valence neutron in 8Li from a measurement of the angular distribution of the single neutron transfer between 8Li and 7Li via the 7Li(8Li,7Li)8 Li reaction at 11 MeV. Using isospin symmetry the 8B ANC has also been calculated and used to infer a value for S17(0) of 20.2 +/- 4.4 eV b.