Abstrakt
Context. Electron-capture on Be-7 is the main production channel for Li-7 in several astrophysical environments.
Theoretical evaluations have to account for not only the nuclear interaction, but also the processes in the plasma in which Be-7 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 Be-7+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 Be-7+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 Be-7 channel of about -4% with respect to what is obtained with the previously adopted rate.
This fact affects the production of neutrinos from B-8, 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 B-8 neutrino flux is improved.