Flavor-Dependent Long-Range Neutrino Interactions in DUNE and T2HK: Synergy Breeds Power

TL;DR

This paper investigates how flavor-dependent long-range neutrino interactions mediated by ultra-light particles could be detected or constrained by upcoming experiments DUNE and T2HK, emphasizing the synergy of their combined analysis.

Contribution

It introduces a comprehensive forecast of the sensitivity of DUNE and T2HK to flavor-dependent long-range neutrino interactions and highlights the enhanced constraints achievable through their combination.

Findings

Individual experiments can constrain long-range neutrino interactions.

Combined analysis improves sensitivity and resolves parameter degeneracies.

Forecasted constraints surpass current bounds.

Abstract

Discovering new neutrino interactions would provide evidence of physics beyond the Standard Model. We focus on flavor-dependent long-range neutrino interactions mediated by ultra-light mediators (masses below $10^{-10}$ eV) from lepton-number gauge symmetries $L_e-L_\mu$, $L_e-L_\tau$, and $L_\mu-L_\tau$. These interactions, sourced by electrons and neutrons in the Earth, Moon, Sun, Milky Way, and the local Universe, could modify neutrino oscillation probabilities. The upcoming long-baseline experiments, DUNE and T2HK, with their large statistics, reduced systematic uncertainties, and well-characterized neutrino beams, will probe these interactions. We forecast that, while individually DUNE and T2HK could constrain these long-range neutrino interactions, their combination lifts parameter degeneracies that weaken individual sensitivity and provides stronger constraints.