### Speaker

### Description

We explore the role of matter effect in the evolution of neutrino oscillation parameters in the presence of non-standard interactions (NSI) of neutrino. We derive approximate analytical expressions for the modified mass-mixing parameters in matter with NSI. We observe that only the NSI parameters in the (2,3) block, namely $\varepsilon_{\mu\tau}$ and $(\gamma - \beta)\equiv (\varepsilon_{\tau\tau} - \varepsilon_{\mu\mu})$ affect the running of $\theta_{23}$. Though all the NSI parameters influence the evolution of $\theta_{13}$, $\varepsilon_{e\mu}$ and $\varepsilon_{e\tau}$ show a stronger impact at the energies relevant for DUNE. The solar mixing angle $\theta_{12}$ quickly approaches to $\sim$ $90^{\circ}$ with increasing energy in both SI and SI+NSI cases. The change in $\Delta m^2_{21,m}$ is quite significant as compared to $\Delta m^2_{31,m}$ both in SI and SI+NSI frameworks for the energies relevant for the 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 baseline length and neutrino energies required to have maximum $\nu_{\mu}$ $\rightarrow$ $\nu_{e}$ transition in the presence NSI. d) study the impact of NSI in $\nu_{\mu}\rightarrow\nu_{\mu}$ disappearance channel.