Impact of Non-unitary Neutrino Mixing on the Physics Potential of NO$$\nu $$A Experiment

The extended theories of Standard Model (SM) require heavy right-handed neutrinos to accommodate observed neutrino oscillation data. If the mass of such sterile neutrinos are of the order of TeV scale, then they can mix with active neutrinos, which leads to non-unitary neutrino mixing. In this paper, we investigate the effect of non-unitary neutrino mixing on the physics potential of the long baseline experiment. We find that non-unitary mixing can deteriorate the sensitivity of NO\(\nu \)A, to the current unknowns in neutrino sector due to the existence of new degeneracies among the oscillation parameters in presence of non-unitary mixing. We also find that the sensitivity to the unknowns enhanced, if we add oscillation data from T2K experiment as it enables to reduce the degeneracies among the oscillation parameters.