Neutrino magnetic dipole portal with low energy neutrino nucleus scattering data

TL;DR

This paper investigates sterile neutrino interactions via magnetic dipole portals across various experiments, providing new constraints on their mass and coupling, especially for low-energy neutrino scattering data.

Contribution

It offers novel experimental constraints on sterile neutrino magnetic dipole moments in the 0.1-50 MeV range using multiple neutrino scattering experiments.

Findings

Dresden-II constrains e-flavor dipole portal for m_N < 0.5 MeV.

COHERENT data probes mu-flavor dipole portal for 10-40 MeV.

Solar neutrino measurements set limits on tau-flavor dipole interactions.

Abstract

Sterile neutrinos that couple to the Standard Model via the neutrino magnetic dipole portals have been extensively studied at various experiments. In this work, we scrutinize these interactions for sterile neutrinos in the mass range of $\unit[0.1]{}-\unit[50]{MeV}$ through the nuclear and electron recoils at various neutrino scattering experiments. For the $e$-flavor specific dipole portal, we demonstrate that Dresden-II can provide leading constraints for $m_N \lesssim \unit[0.5]{MeV}$, setting aside currently unresolved theoretical uncertainties. For the $\mu$-flavor case, we show that the COHERENT experiment can probe a unique parameter region for $m_N$ in the range of $\unit[10]{}-\unit[40]{MeV}$ with the full dataset collected by the CsI[Na] scintillation detector, including both the energy and timing structure of the neutrino beam. We also present limits on the parameter regions of the $\tau$-flavor dipole portal using measurements of the solar neutrino flux from dark matter direct detection experiments.