Abstract
We explore the role of matter effect in the evolution of neutrino oscillation parameters in the presence of lepton-flavor-conserving and lepton-flavor-violating neutralcurrent non-standard interactions (NSI) of the neutrino. We derive simple approximate analytical expressions showing the evolution of mass-mixing parameters in matter with energy in the presence of standard interactions (SI) and SI+NSI (considering both positive and negative values of real NSI parameters). We observe that only the NSI parameters in the (2,3) block, namely epsilon(mu tau) and (gamma - beta) (epsilon(tau tau) - epsilon(mu mu)) affect the modification of theta(23). Though all the NSI parameters influence the evolution of theta(13), epsilon(e mu) and epsilon(e tau) show a stronger impact at the energies relevant for DUNE. The solar mixing angle theta(12) quickly approaches to similar to 90 degrees with increasing energy in both SI and SI+NSI cases. The change in Delta m(21,m)(2) is quite significant as compared to Delta m(31, m)(2) both in SI and SI+NSI frameworks for the energies relevant for DUNE baseline. Flipping the signs of the NSI parameters alters the way in which mass-mixing parameters run with energy. We demonstrate the utility of our approach in addressing several important features related to neutrino oscillation such as: a) unraveling interesting degeneracies between theta(23) and NSI parameters, b) estimating the resonance energy in presence of NSI when theta(13) in matter becomes maximal, c) figuring out the required baselines and energies to have maximal matter effect in nu(mu) -> nu(e) transition in the presence of different NSI parameters, and d) studying the impact of NSI parameters epsilon(mu tau) and (gamma - beta) on the nu(mu) -> nu(mu) survival probability.