Determination of the B8 neutrino energy spectrum using trapped ions

Abstract

The ${\ensuremath{\beta}}^{+}$ decay of $^{8}\mathrm{B}$ provides the dominant source of solar neutrinos above 2 MeV. Consequently, experiments that detect neutrinos from the sun require an accurate determination of the $^{8}\mathrm{B}$ neutrino energy spectrum. In this work, the $\ensuremath{\beta}$-decay Paul trap surrounded by double-sided silicon strip detectors was utilized to precisely measure the decay products of trapped $^{8}\mathrm{B}$ ions. The results were used to determine the $^{8}\mathrm{Be}$ final-state distribution and to reconstruct the neutrino energy spectrum. This measurement using trapped ions is the first of its kind and puts the neutrino energy spectrum on much firmer footing by discriminating between recently reported values for the maximum of the final-state distribution.