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 $0.69\times 10^{-17}$ eV), the fast-averaging over an oscillation cycle leads to a modification of the measured oscillation parameters. We present a specific $\hat{I}¼-\ddot{I}„$ symmetric model in which the measured value of $\hat{I}{¸}_{13}$ 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 $3\ddot{I}ƒ$ C.L. for bimaximal, tribimaximal and hexagonal mixing, while JUNO can rule it out at more than $6\ddot{I}ƒ$ C.L. by precisely measuring both $\hat{I}{¸}_{12}$ and $\hat{I}{¸}_{13}$.

21 pages, 2 figures. Version to appear in JHEP