Stringent constraints on nonstandard neutrino interactions using high-purity $\nu_\mu\, {\rm CC}$ events in IceCube DeepCore
Published in Physical Review D, 2026
Recommended citation: J Krishnamoorthi, Anil Kumar, and Sanjib Kumar Agarwalla, "Stringent constraints on nonstandard neutrino interactions using high-purity $\nu_\mu\, {\rm CC}$ events in IceCube DeepCore", Physical Review D, 114 (2026), 075009. https://doi.org/10.1103/2n9h-csnl
Abstract: The neutral-current (NC) nonstandard interactions (NSIs) of neutrinos with fermions can modify the flavor oscillations of atmospheric neutrinos as they propagate through the Earth. We present constraints on the NC-NSI parameters $\varepsilon_{\mu\tau}$ and $\varepsilon_{\tau\tau}-\varepsilon_{\mu\mu}$ (one at a time) using a high-purity sample of $\nu_{\mu}$ charged-current atmospheric neutrino events collected by IceCube DeepCore over 7.5 years of livetime. These two parameters significantly affect the $\nu_\mu$ disappearance channel for which this golden event sample is optimized by IceCube Collaboration. The best fit to this dataset is consistent with no NSI hypothesis, and we place the stringent constraints $-\,0.0094 < \varepsilon_{\mu\tau} < 0.0079$ and $-\,0.031 < \varepsilon_{\tau\tau}-\varepsilon_{\mu\mu} < 0.029$ at the 90% confidence level, assuming normal mass ordering.