The Sterile-Active Neutrino Flavor Model: the Imprint of Dark Matter on the Electron Neutrino Spectra

Contact interactions between sterile neutrinos and dark matter particles in a hidden sector have been suggested as a good solution to simultaneously resolve the dark matter problem and anomalies in neutrino experiments. In this non-standard particle physics model, sterile and active neutrinos change their through vacuum oscillations and matter (or Mikheyev--Smirnov--Wolfenstein) oscillations, in which the latter mechanism of flavor oscillation depends strongly on the concentration of dark matter in the Sun's core. We found that a large concentration of dark matter in the Sun's interior changes substantially the shape of ${\rm ^8B}$ and $\rm hep$ electron neutrino spectra, but has an insignificant impact on the other neutrino spectra (i.e., $\rm pp$, $\rm pep$, $\rm ^7Be$ and $\rm ^{15}O$, $\rm ^{13}N$ and $\rm ^{17}F$). The strength of the interaction of the dark matter particles with neutrinos depends on an effective coupling constant, $G_\chi$, which is an analog of the Fermi constant for the hidden sector. By using the latest $\rm ^8B$ solar neutrino flux, we found that $G_\chi$ must be smaller than $\rm 0.5\times 10^9$ $G_{\rm F}$ for this particle physics model to be in agreement with the data.