Search for CP-Violating Neutrino Nonstandard Interactions with the NOvA Experiment

Phys Rev Lett. 2024 Nov 15;133(20):201802. doi: 10.1103/PhysRevLett.133.201802.

Abstract

This Letter reports a search for charge-parity (CP) symmetry violating nonstandard interactions (NSI) of neutrinos with matter using the NOvA Experiment, and examines their effects on the determination of the standard oscillation parameters. Data from ν_{μ}(ν[over ¯]_{μ})→ν_{μ}(ν[over ¯]_{μ}) and ν_{μ}(ν[over ¯]_{μ})→ν_{e}(ν[over ¯]_{e}) oscillation channels are used to measure the effect of the NSI parameters ϵ_{eμ} and ϵ_{eτ}. With 90% CL the magnitudes of the NSI couplings are constrained to be |ϵ_{eμ}|≲0.3 and |ϵ_{eτ}|≲0.4. A degeneracy at |ϵ_{eτ}|≈1.8 is reported, and we observe that the presence of NSI limits sensitivity to the standard CP phase δ_{CP}.