Electron capture on ^{8}B nuclei and Superkamiokande results

TL;DR

This paper investigates whether electron capture on ^{8}B nuclei could explain the observed spectral deformation in Superkamiokande solar neutrino data, concluding it is unlikely due to the flux discrepancy.

Contribution

The study assesses a potential nuclear process as an explanation for spectral deformation, providing a quantitative comparison with observed data and theoretical predictions.

Findings

Proposed u-e scattering from ^{8}B electron capture could match data if flux was higher.

Theoretical flux prediction is four orders of magnitude lower than needed.

Electron capture on ^{8}B is unlikely to explain spectral deformation.

Abstract

The energy spectrum of recoil electrons from solar neutrino scattering, as observed by Superkamiokande, is deformed with respect to that expected from SSM calculations. We considered \nu-e scattering from neutrinos produced by the electron-capture on ^{8}B nuclei, e^{-}+^{8}B --> ^{8}Be^{*}+\nu_{e}, as a possible explanation of the spectral deformation. A flux \Phi_{eB}\simeq 10^{4} cm^{-2} s^{-1} could account for Superkamiokande solar neutrino data. However this explanation is untenable, since the theoretical prediction, \Phi_{eB}=(1.3+-0.2) cm^{-2} s^{-1}, is smaller by four orders of magnitude.