Neutrino Non-Standard Interactions from LLE-type R-parity Violation

TL;DR

This paper investigates how R-parity-violating supersymmetry with light third-generation sleptons can induce measurable neutrino non-standard interactions, constrained by experimental data, with potential percent-level effects.

Contribution

It systematically classifies coupling patterns, derives effective NSI interactions, and analyzes experimental constraints within split-family R-parity-violating SUSY models.

Findings

Percent-level NSI possible in certain channels.

Largest NSI magnitudes: ε_ee ≈ 8%, ε_μμ ≈ 3.8%.

Other NSI entries are typically sub-percent, e.g., ε_μτ ≈ -0.3%.

Abstract

We study neutrino non-standard interactions (NSI) induced by the trilinear $LLE$ couplings in $R$-parity-violating supersymmetry in a split-family spectrum where third-generation sleptons can be comparatively light. We systematically classify the relevant coupling patterns, derive the corresponding effective interactions and NSI parameters, and confront the resulting parameter space with a broad set of experimental constraints. We find that percent-level NSI can be realized in selected channels, with the largest magnitudes reaching $\varepsilon_{ee}\simeq 8\%$ and $\varepsilon_{\mu\mu}\simeq 3.8\%$, while other entries are typically restricted to the sub-percent level (including $\varepsilon_{\mu\tau}\simeq -0.3\%$ in the viable off-diagonal case). We also highlight the structural origin of the different constraint patterns between $\widetilde{\tau}_R$- and $\widetilde{\tau}_L$-mediated scenarios and comment on the relation to the Zee model.