Expected sensitivity to test of standard solar models with future solar CNO neutrino flux measurement

Abstract

Standard solar models built from spectroscopy and from the helioseismology predicted inconsistent solar metallicity. Solar neutrino fluxes can be used to test two models. Hypothesis test was performed using 7Be, 8B CNO neutrino fluxes. Current experimental results already disfavored the low metallicity standard solar model at a significance of 2.1 σ. Considering new experiments that can improve the precision of the measured CNO neutrino flux are being planned, it is important to study their potentiality to discriminating two standard solar models. We evaluated the expected significance to reject the low metallicity solar model where the assumed central value and uncertainty of the measured CNO neutrino flux vary within the range of 3.5 × 108 -- 8 × 108 s−1cm−2 and 1%--20%, respectively. It was found that the potentiality of future experiments to reject the low metallicity standard solar model strongly depends on the central value of the CNO neutrino flux measurement. When the central value is the same as the value measured by Borexino in 2020, the required precision to reach 3 σ and 5 σ are 20% and 8%, respectively, which are both achievable.