Nonstandard interactions in neutrino oscillations and the recent Daya Bay and T2K experiments.

We study the possible constraints on nonstandard interaction (NSIs) in a model-independent way by considering the recent results from the T2K and Daya Bay neutrino oscillations experiments. Using the perturbation method we present generic formulas (suitable for T2K baseline and for large θ13 as evident from Daya Bay) for the probability of oscillation for vμ→ ve, taking into account NSIs at the source (∈s), the detector (∈d), and during propagation (∈m) of neutrinos through matter. Two separate cases of perturbation with small (slightly large) NSI [∈mαβ~0.03(0.18)] are discussed in detail. Using various possible presently allowed NSI values we reanalyze numerically the θ13 -- δ allowed region given by recent T2K experimental data. We obtain model-independent constraints on NSIs in the δ -- ∈mαβ plane using the θ13 value as measured by Daya Bay, where δ is the CP violating phase. Depending on δ values, significant constraints on ∈eT and ∈TT, in particular, are possible for both hierarchies of neutrino masses. Corresponding to T2K's 66% confidence level result, the constraints on ∈TT are shown to be independent of any 5 value. [ABSTRACT FROM AUTHOR]