${{\mathit p}}{{\mathit p}}$ solar-neutrino flux measured via ${{\mathit \nu}}{{\mathit e}}$ elastic scattering. This process is sensitive to all active neutrino flavors, but with reduced sensitivity to ${{\mathit \nu}_{{\mu}}}$, ${{\mathit \nu}_{{\tau}}}$ due to the cross section difference, ${\mathit \sigma (}{{\mathit \nu}}_{{{\mathit \mu}},{{\mathit \tau}}}{{\mathit e}}{)}$ $\sim{}$ 0.3 ${\mathit \sigma (}$ ${{\mathit \nu}_{{e}}}{{\mathit e}}{)}$. If the ${{\mathit p}}{{\mathit p}}$ solar-neutrino flux involves nonelectron flavor active neutrinos, their contribution to the flux is $\sim{}$ 0.3 times of ${{\mathit \nu}_{{e}}}$.

VALUE ($ 10^{10} $ cm${}^{-2}$ s${}^{-1}$) DOCUMENT ID TECN  COMMENT • • We do not use the following data for averages, fits, limits, etc. • • $4.4$ $\pm0.5$ 1 BELLINI 2014 A BORX average flux 1  BELLINI 2014A reports ${{\mathit p}}{{\mathit p}}$ solar-neutrino flux measured via ${{\mathit \nu}}{{\mathit e}}$ elastic scattering. The data were collected between January 2012 and May 2013, corresponding to 408 days of data. The ${{\mathit p}}{{\mathit p}}$ neutrino interaction rate in Borexino is measured to be $144$ $\pm13$ $\pm10$ counts/(day$\cdot{}$100 ton) by fitting the measured energy spectrum of events in the $165 - 590$ keV recoil electron kinetic energy window with the expected signal + background spectrum. The listed flux value ${{\mathit \phi}_{{ES}}}$( ${{\mathit p}}{{\mathit p}}$ ) is calculated from the observed rate and the number of ($33.07$ $\pm0.03$) $ \times 10^{30}$ electrons for 100 tons of the Borexino scintillator, and the ${{\mathit \nu}_{{e}}}{{\mathit e}}$ integrated cross section over the ${{\mathit p}}{{\mathit p}}$ neutrino spectrum, ${\mathit \sigma (}$ ${{\mathit \nu}_{{e}}}{{\mathit e}}{)}$ = $11.38 \times 10^{-46}~$cm${}^{2}$.

References:

BELLINI 2014A NAT 512 383 Neutrinos from the Primary Proton-Proton Fusion Process in the Sun