Low-energy neutrino responses for 71Ga by electron capture rates, charge exchange reactions and shell model calculations

Abstract

Weak Gamow-Teller (GT) responses for low-lying states in ${}^{71}\mathrm{Ga}$ are crucial for studying low-energy solar neutrinos and the Ga anomaly, i.e., the possible transition to the sterile state. The responses for the ground state, the first excited state, and the second excited state are evaluated for the first time using the experimental electron capture rates, the experimental charge exchange reaction (CER) rates corrected for the tensor-interaction effect and the theoretical interacting shell model (ISM) calculations. The contributions from the two excited states to the solar and ${}^{51}\mathrm{Cr}$ neutrinos are found to be $4.2\pm 1.2\%$ of that for the ground state. This is slightly larger than the ISM values but little smaller than the CER values without corrections for the tensor interaction effect. The Ga anomaly is far beyond the uncertainty of the obtained nuclear responses.

arXiv commentsubmitted

References in corpus (13)

• Reanalysis of the GALLEX solar neutrino flux and source experiments
• Statistical Significance of the Gallium Anomaly
• Thick-Restart Block Lanczos Method for Large-Scale Shell-Model Calculations
• Measurement of the response of a Ga solar neutrino experiment to neutrinos from an 37Ar source
• Gallium Solar Neutrino Experiments: Absorption Cross sections, Neutrino spectra, and Predicted Event Rates
• Sterile Neutrinos
• Results from the Baksan Experiment on Sterile Transitions (BEST)
• eV-scale Sterile Neutrinos
• The (t,3He) and (3He,t) reactions as probes of Gamow-Teller strength
• A Search for Electron Neutrino Transitions to Sterile States in the BEST Experiment
• The gallium anomaly revisited
• Cross Section Uncertainties in the Gallium Neutrino Source Experiments
• Neutrino-4 anomaly: oscillations or fluctuations?