Abstract
Knowledge of the energy spectrum of neutrinos is important for interpreting experiments that detect energetic neutrinos from the Sun. The neutrino spectrum deviates from the allowed -decay approximation because of the broad -unstable final state and recoil order corrections. We have measured the total energy of the particles emitted following the decay of . The measured spectrum is inconsistent with a recent measurement of comparable precision. The spectrum is fit using the R-matrix approach, which gives a functional form for the -decay strength function for the transition from to the accessible excitation energies in . Both the positron and neutrino energy spectra, corrected for recoil order effects, are constructed from the strength function. The positron spectrum is in good agreement with a previous direct measurement. The neutrino spectrum disagrees with previous experiments.
7 More- Received 21 June 2004
DOI:https://doi.org/10.1103/PhysRevC.73.025503
©2006 American Physical Society