RESUMO
The scalar nonstandard interactions (NSI) can also introduce matter effect for neutrino oscillation in a medium. Especially the recent Borexino data prefer nonzero scalar NSI, η_{ee}=-0.16. In contrast to the conventional vector NSI, the scalar type contributes as a correction to the neutrino mass matrix rather than the matter potential. Consequently, the scalar matter effect is energy independent while the vector one scales linearly with neutrino energy. This leads to significantly different phenomenological consequences in reactor, solar, atmospheric, and accelerator neutrino oscillations. A synergy of different types of experiments, especially those with matter density variation, is necessary to identify the scalar NSI and guarantee the measurement of CP violation at accelerator experiments.
RESUMO
We propose to use the unique event topology and reconstruction capabilities of liquid argon time projection chambers to study sub-GeV atmospheric neutrinos. The detection of low energy recoiled protons in DUNE allows for a determination of the leptonic CP-violating phase independent from the accelerator neutrino measurement. Our findings indicate that this analysis can exclude a range of values of δ_{CP} beyond the 3σ level. Moreover, the determination of the sub-GeV atmospheric neutrino flux will have important consequences in the detection of diffuse supernova neutrinos and in dark matter experiments.