Testing neutrino electromagnetic properties at current and future dark matter experiments

TL;DR

This paper uses current and future dark matter detection experiments to set new bounds on neutrino electromagnetic properties, highlighting the potential for DARWIN to measure the neutrino charge radius.

Contribution

It provides the first combined analysis of multiple experiments with conservative background treatment to constrain neutrino electromagnetic properties and forecasts future measurement capabilities.

Findings

Strong bounds on neutrino magnetic moments and millicharges from current data.

DARWIN could measure the electron neutrino charge radius for the first time.

Conservative background treatment improves the reliability of the bounds.

Abstract

We analyze data from the dark matter direct detection experiments PandaX-4T, LUX-ZEPLIN and XENONnT to place bounds on neutrino electromagnetic properties (magnetic moments, millicharges, and charge radii). We also show how these bounds will improve at the future facility DARWIN. In our analyses we implement a more conservative treatment of background uncertainties than usually done in the literature. From the combined analysis of all three experiments we can place very strong bounds on the neutrino magnetic moments and on the neutrino millicharges. We show that even though the bounds on the neutrino charge radii are not very strong from the analysis of current data, DARWIN could provide the first measurement of the electron neutrino charge radius, in agreement with the Standard Model prediction.