Constraining neutrino electromagnetic properties with recent low-energy electron recoil data at dark matter direct detection experiments

Abstract: Neutrinos that are elastically scattered off atomic electrons provide a unique opportunity to investigate the Standard Model (SM) and beyond SM physics. In this work, we explore the new physics effects of neutrino electromagnetic properties through elastic neutrino-electron scattering using solar neutrinos at the low energy range of PandaX-4T and XENONnT experiments. The properties of interest include the neutrino magnetic moment, millicharge, and charge radius, all of which are natural consequences of non-zero neutrino masses. We investigate their effects by incorporating each property into the Standard Model (SM) framework, given the measured the solar neutrino flux. By analyzing the latest Run 0 and Run 1 datasets from the PandaX-4T experiment, together with recent results from XENONnT, we derive new constraints on each electromagnetic property of neutrino. We present both flavor-independent results, obtained using a common parameter for all three neutrino flavors, and flavor-dependent results, derived by marginalizing over the three neutrino flavor components. Bounds we obtained are comparable or improved compared to those reported in the previous studies.