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

Abstract

Context. Electron-capture on 7Be is the main production channel for 7Li in several astrophysical environments. Theoretical evaluations have to account for not only the nuclear interaction, but also the processes in the plasma in which 7Be 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. Aims. In the framework of fundamental solar physics, we consider a recent evaluation for the 7Be+e− rate, which has not been used up to now, in the estimate of neutrino fluxes. Methods. We analyzed the effects of the new assumptions on standard solar models (SSMs) and compared the results obtained by adopting the revised 7Be+e− rate to those obtained by that reported in a widely used compilation of reaction rates (ADE11). Results. We found that new SSMs yield a maximum difference in the efficiency of the 7Be channel of about −4% with respect to what is obtained with the previously adopted rate. This fact affects the production of neutrinos from 8B, 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. Conclusions. The agreement with the Sudbury Neutrino Observatory measurements of the neutral current component of the 8B neutrino flux is improved.