Effects of a revised 7Be e- -capture rate on solar neutrino fluxes

Abstract

Context. Electron-capture on <SUP>7</SUP>Be is the main production channel for <SUP>7</SUP>Li in several astrophysical environments. Theoretical evaluations have to account for not only the nuclear interaction, but also the processes in the plasma in which <SUP>7</SUP>Be ions and electrons interact. In recent decades several estimates were presented, pointing out that the theoretical uncertainty in the rate is in general of a few percent. <BR /> Aims: In the framework of fundamental solar physics, we consider a recent evaluation for the <SUP>7</SUP>Be+e<SUP>-</SUP> rate, which has not been used up to now, in the estimate of neutrino fluxes. <BR /> Methods: We analyzed the effects of the new assumptions on standard solar models (SSMs) and compared the results obtained by adopting the revised <SUP>7</SUP>Be+e<SUP>-</SUP> rate to those obtained by that reported in a widely used compilation of reaction rates (ADE11). <BR /> Results: We found that new SSMs yield a maximum difference in the efficiency of the <SUP>7</SUP>Be channel of about -4% with respect to what is obtained with the previously adopted rate. This fact affects the production of neutrinos from <SUP>8</SUP>B, increasing the relative flux up to a maximum of 2.7%. Negligible variations are found for the physical and chemical properties of the computed solar models. <BR /> Conclusions: The agreement with the Sudbury Neutrino Observatory measurements of the neutral current component of the <SUP>8</SUP>B neutrino flux is improved. <P />The electron-capture table is only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr/">http://cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/623/A126">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/623/A126