Search for CP-violating Neutrino Non-Standard Interactions with the NOvA Experiment

This Letter reports a search for charge-parity (CP) symmetry violating non-standard interactions (NSI) of neutrinos with matter using the NOvA Experiment, and examines their effects on the determination of the standard oscillation parameters. Data from \(\nu_{\mu}(\bar{\nu}_{\mu})\rightarrow\nu_{\mu}(\bar{\nu}_{\mu})\) and \(\nu_{\mu}(\bar{\nu}_{\mu})\rightarrow\nu_{e}(\bar{\nu}_{e})\) oscillation channels are used to measure the effect of the NSI parameters \(\varepsilon_{e\mu}\) and \(\varepsilon_{e\tau}\). With 90% C.L. the magnitudes of the NSI couplings are constrained to be \(|\varepsilon_{e\mu}| \, \lesssim 0.3\) and \(|\varepsilon_{e\tau}| \, \lesssim 0.4\). A degeneracy at \(|\varepsilon_{e\tau}| \, \approx 1.8\) is reported, and we observe that the presence of NSI limits sensitivity to the standard CP phase \(\delta_{\tiny\text{CP}}\).