Projected sensitivities of the LUX-ZEPLIN (LZ) experiment to new physics via low-energy electron recoils

TL;DR

This paper projects the LZ experiment's potential to detect various new physics phenomena through low-energy electron recoil signals, achieving world-leading sensitivities due to its large exposure and low background rates.

Contribution

It provides comprehensive sensitivity projections for multiple new physics signals in the LZ experiment, using a consistent analysis framework and emphasizing its potential for groundbreaking discoveries.

Findings

Expected world-leading sensitivities for neutrino magnetic moment and millicharge

High sensitivity to solar axions and axion-like particles

Strong constraints on hidden photons, mirror dark matter, and leptophilic dark matter

Abstract

LUX-ZEPLIN (LZ) is a dark matter detector expected to obtain world-leading sensitivity to weakly interacting massive particles (WIMPs) interacting via nuclear recoils with a ~7-tonne xenon target mass. This manuscript presents sensitivity projections to several low-energy signals of the complementary electron recoil signal type: 1) an effective neutrino magnetic moment and 2) an effective neutrino millicharge, both for pp-chain solar neutrinos, 3) an axion flux generated by the Sun, 4) axion-like particles forming the galactic dark matter, 5) hidden photons, 6) mirror dark matter, and 7) leptophilic dark matter. World-leading sensitivities are expected in each case, a result of the large 5.6t 1000d exposure and low expected rate of electron recoil backgrounds in the $<$100keV energy regime. A consistent signal generation, background model and profile-likelihood analysis framework is used throughout.