Search for New Physics via Low-Energy Electron Recoils with a 4.2 Tonne\times Year Exposure from the LZ Experiment

Abstract

We report results from searches for new physics models via electron recoils using data collected by the LUX-ZEPLIN (LZ) experiment during its first two science runs, with a total exposure of 4.2 tonne-years. The observed data are consistent with a background-only hypothesis. Constraints are derived for several new physics models that predict electronic recoil signals, including electromagnetic interactions of solar neutrinos, solar axion-like particles (ALPs), mirror dark matter, and the absorption of bosonic dark matter candidates. These results represent the most stringent constraints to date for solar ALPs with keV-scale masses and mirror dark matter, and they are competitive with existing limits for other investigated models.