Testing for large extra dimensions with neutrino oscillations

We consider a model where sterile neutrinos can propagate in a large compactified extra dimension giving rise to Kaluza-Klein (KK) modes and the standard model left-handed neutrinos are confined to a 4-dimensional spacetime brane. The KK modes mix with the standard neutrinos modifying their oscillation pattern. We examine former and current experiments such as CHOOZ, KamLAND, and MINOS to estimate the impact of the possible presence of such KK modes on the determination of the neutrino oscillation parameters and simultaneously obtain limits on the size of the largest extra dimension. We found that the presence of the KK modes does not essentially improve the quality of the fit compared to the case of the standard oscillation. By combining the results from CHOOZ, KamLAND, and MINOS, in the limit of a vanishing lightest neutrino mass, we obtain the stronger bound on the size of the extra dimension as ∼1.0(0.6) μm at 99% C.L. for normal (inverted) mass hierarchy. If the lightest neutrino mass turns out to be larger, 0.2 eV, for example, we obtain the bound ∼0.1 μm. We also discuss the expected sensitivities on the size of the extra dimension for future experiments such as Double CHOOZ, T2K, and NOνA.