Light scalar dark matter at neutrino oscillation experiments

Abstract

Couplings between light scalar dark matter (DM) and neutrinos induce a perturbation to the neutrino mass matrix. If the DM oscillation period is smaller than ten minutes (or equivalently, the DM particle is heavier than 0.69×10−17 eV), the fast-averaging over an oscillation cycle leads to a modification of the measured oscillation parameters. We present a specific μ − τ symmetric model in which the measured value of θ13 is entirely generated by the DM interaction, and which reproduces the other measured oscillation parameters. For a scalar DM particle lighter than 10−15 eV, adiabatic solar neutrino propagation is maintained. A suppression of the sensitivity to CP violation at long baseline neutrino experiments is predicted in this model. We find that DUNE cannot exclude the DM scenario at more than 3σ C.L. for bimaximal, tribimaximal and hexagonal mixing, while JUNO can rule it out at more than 6σ C.L. by precisely measuring both θ12 and θ13.