Nonstandard interactions jeopardizing the hierarchy sensitivity of DUNE

In this work we consider the effect of non-standard interactions (NSI) on the propagation of neutrinos through matter and how it affects the hierarchy sensitivity of the DUNE experiment. We emphasize on the special case when the diagonal NSI parameter ϵee=−1 and nullifies the standard matter effect. We show that, if in addition, there is maximal CP violation then this gives rise to an exact intrinsic hierarchy degeneracy, in the appearance channel, irrespective of the baseline and energy. Introduction of off-diagonal NSI parameter, ϵeτ, shifts the position of intrinsic degeneracy to a different ϵee. Moreover the unknown magnitude and phases of the off-diagonal NSI parameters can give additional degeneracies. Overall, given the current model independent limits on NSI parameters, no hierarchy sensitivity can be observed in the DUNE experiment if NSIs exist in nature. A signal of neutrino mass hierarchy at DUNE will therefore be able to rule out certain ranges of the NSI parameters.