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

¹ Gran Sasso Science Institute, Viale Francesco Crispi, 7, 67100 L’Aquila, Italy
e-mail: diego.vescovi@gssi.it
² INFN, Section of Perugia, Via A. Pascoli snc, 06123 Perugia, Italy
³ INAF, Observatory of Abruzzo, Via Mentore Maggini snc, 64100 Teramo, Italy
⁴ University of Perugia, Department of Physics and Geology, Via A. Pascoli snc, 06123 Perugia, Italy
⁵ INFN, Laboratori Nazionali del Gran Sasso, Via G. Acitelli, 22, Assergi, L’Aquila, Italy
⁶ Division of physics School of Science and Technology Università di Camerino, Italy
⁷ Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
⁸ European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*-FBK) and Trento Institute for Fundamental Physics and Applications (TIFPA-INFN), Trento, Italy

Received: 28 December 2018
Accepted: 4 February 2019

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.