### Speaker

### Description

We explore the role of matter effect in the evolution of neutrino oscillation parameters in the presence of non-standard interactions (NSIs). We derive approximate analytical expressions showing evolution of mass-mixing parameters in matter and in presence of NSIs. We observe that only the NSIs in (2,3) block ($\varepsilon_{\mu\mu}$, $\varepsilon_{\tau\tau}$, and $\varepsilon_{\mu\tau}$) affect the running of $\theta_{23}$. $\varepsilon_{e\mu}$ and $\varepsilon_{e\tau}$ have stronger impact on the $\theta_{13}$ evolution. We show the utility of our approach in addressing some important features related to neutrino oscillation: a) unraveling interesting degeneracies between $\theta_{23}$ and NSI parameters, b) estimating the resonance energy in presence of NSIs when $\theta_{13}$ in matter becomes maximal, c) estimating the required baseline length and neutrino energies to have maximal matter effect in $\nu_{\mu}$ $\rightarrow$ $\nu_{e}$ transition in presence of NSI parameters, and d) studying the impact of NSIs in (2,3) block on the $\nu_{\mu}$ $\to$ $\nu_{\mu}$ survival probability.