The ${}^8$B Neutrino Spectrum

Abstract

Knowledge of the energy spectrum of ${}^8$B neutrinos is an important ingredient for interpreting experiments that detect energetic neutrinos from the Sun. The neutrino spectrum deviates from the allowed approximation because of the broad alpha-unstable ${}^8$Be final state and recoil order corrections to the beta decay. We have measured the total energy of the alpha particles emitted following the beta decay of ${}^8$B. The measured spectrum is inconsistent with some previous measurements, in particular with a recent experiment of comparable precision. The beta decay strength function for the transition from ${}^8$B to the accessible excitation energies in ${}^8$Be is fit to the alpha energy spectrum using the R-matrix approach. 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, particularly for neutrino energies above 12 MeV.

15 pages, 13 figures, 4 tables, submitted to Phys. Rev. C, typos corrected

References in corpus (3)

• First Results from KamLAND: Evidence for Reactor Anti-Neutrino Disappearance
• Measurement of the Total Active 8B Solar Neutrino Flux at the Sudbury Neutrino Observatory with Enhanced Neutral Current Sensitivity
• Status of three-neutrino oscillations after the SNO-salt data

Cited by in corpus (45)

• Solar fusion cross sections II: the pp chain and CNO cycles
• Combined Analysis of all Three Phases of Solar Neutrino Data from the Sudbury Neutrino Observatory
• Solar neutrino results in Super-Kamiokande-III
• Independent Measurement of the Total Active 8B Solar Neutrino Flux Using an Array of 3He Proportional Counters at the Sudbury Neutrino Observatory
• Solar Neutrino Measurements in Super-Kamiokande-IV
• Final results of Borexino Phase-I on low energy solar neutrino spectroscopy
• Low Energy Threshold Analysis of the Phase I and Phase II Data Sets of the Sudbury Neutrino Observatory
• Current unknowns in the three neutrino framework
• Production of Radioactive Isotopes through Cosmic Muon Spallation in KamLAND
• Grand Unified Neutrino Spectrum at Earth: Sources and Spectral Components
• DUNE as the Next-Generation Solar Neutrino Experiment
• Diffuse Supernova Neutrino Background Search at Super-Kamiokande
• Measurement of the 8B Solar Neutrino Flux with the KamLAND Liquid Scintillator Detector
• The Sudbury Neutrino Observatory
• Measurement of the ${\nu }_e$ and Total ${}^8$B Solar Neutrino Fluxes with the Sudbury Neutrino Observatory Phase-III Data Set
• A Search for Neutrinos from the Solar hep Reaction and the Diffuse Supernova Neutrino Background with the Sudbury Neutrino Observatory
• Improved measurement of ${}^8$B solar neutrinos with 1.5 kt y of Borexino exposure
• First calculation of cosmic-ray muon spallation backgrounds for MeV astrophysical neutrino signals in Super-Kamiokande
• Developing the MeV potential of DUNE: Detailed considerations of muon-induced spallation and other backgrounds
• Measurement of the ${}^8$B Solar Neutrino Flux in SNO+ with Very Low Backgrounds
• Solar neutrino measurements using the full data period of Super-Kamiokande-IV
• Double-Weak Decays of ${}^{124}$Xe and ${}^{136}$Xe in the XENON1T and XENONnT Experiments
• The Monte Carlo simulation of the Borexino detector
• Precision ${\bar{\nu }}_e$-electron Scattering Measurements with IsoDAR to Search for New Physics
• MeV-scale performance of water-based and pure liquid scintillator detectors
• Neutrino Capture Reactions on ${}^{40}$Ar
• Solar neutrino physics
• Search for $hep$ solar neutrinos and the diffuse supernova neutrino background using all three phases of the Sudbury Neutrino Observatory
• Solar fusion III: New data and theory for hydrogen-burning stars
• Test of the Conserved Vector Current Hypothesis by beta-ray Angular Distribution Measurement in the Mass-8 System
• Dark matter imprint on ${}^8$B neutrino spectrum
• Results from Super-Kamiokande
• Search for solar electron anti-neutrinos due to spin-flavor precession in the Sun with Super-Kamiokande-IV
• Nonmesonic weak decay spectra of ${}_{\Lambda }^4$He
• New neutrino physics and the altered shapes of solar neutrino spectra
• Search for the second forbidden beta decay of 8B to the ground state of 8Be
• PEANUTS: a software for the automatic computation of solar neutrino flux and its propagation within Earth
• Measurement of the ${}^8$B Solar Neutrino Flux Using the Full SNO+ Water Phase Dataset
• First Evidence of Solar Neutrino Interactions on ${}^{13}$C
• The spectroscopy of solar sterile neutrinos
• The Sterile-Active Neutrino Flavor Model: the Imprint of Dark Matter on the Electron Neutrino Spectra
• A $\nu$ look at the Sun: Probing the conditions of the solar core using ${}^8$B neutrinos
• Towards First Detection of the Solar MSW Transition With JUNO
• Solar neutrino physics on the beginning of 2017
• Measurement of the solar neutrino interaction rate below 3.49 MeV in Super-Kamiokande-IV