Implications of the variability of the solar neutrino flux

Abstract

Analyses of the Cl and Ga solar neutrino data yield statistically compelling evidence for rotational (and related) modulations of the solar neutrino flux. While a neutrino transition magnetic moment and the Resonant-Spin-Flavor-Precession (RSFP) process have given at least as good a fit to time-averaged solar data as any other solution, the observed variability fits no present solution. The Cl data show mainly a synodic rotation frequency of 12.88 y −1 (period 28.4 d) which display a latitudinal effect, just as does exactly the same frequency seen by SXT in coronal X-rays. While each data set has some of the other's dominant frequency, that of Ga is mainly 13.59 y −1, but it is equatorial, just as are the SXT coronal X-rays of that same frequency. The Ca data in narrow bins show one peak of nearly non-oscillational flux value and the other of about half that, with bimodality at the 99.99% CL. Convolution with SOHO/MDI helioseismology data shows the Ca effect is on the solar equator in the convection zone at 0.8 R ⊙, yielding exactly the E Δm 2 value used for RSFP solutions to suppress 7Be neutrinos; hence Δm 2 ∼ 10 −8 eV 2. The data can be explained by two rotating solar fields, the higher latitude one being anchored in the radiative zone, the tilt of the solar axis, and the Ga data being nearly all pp neutrinos produced at ∼ 0.2 R ⊙, whereas the others come from the solar center (∼ 0.05 R ⊙) .