Search for annual and diurnal rate modulations in the LUX experiment
  Various dark matter models predict annual and diurnal modulations of dark
matter interaction rates in Earth-based experiments as a result of the Earth's
motion in the halo. Observation of such features can provide generic evidence
for detection of dark matter interactions. This paper reports a search for both
annual and diurnal rate modulations in the LUX dark matter experiment using
over 20 calendar months of data acquired between 2013 and 2016. This search
focuses on electron recoil events at low energies, where leptophilic dark
matter interactions are expected to occur and where the DAMA experiment has
observed a strong rate modulation for over two decades. By using the innermost
volume of the LUX detector and developing robust cuts and corrections, we
obtained a stable event rate of 2.3$\pm$0.2~cpd/keV$_{\text{ee}}$/tonne, which
is among the lowest in all dark matter experiments. No statistically
significant annual modulation was observed in energy windows up to
26~keV$_{\text{ee}}$. Between 2 and 6~keV$_{\text{ee}}$, this analysis
demonstrates the most sensitive annual modulation search up to date, with
9.2$\sigma$ tension with the DAMA/LIBRA result. We also report no observation
of diurnal modulations above 0.2~cpd/keV$_{\text{ee}}$/tonne amplitude between
2 and 6~keV$_{\text{ee}}$.
