Signal yields, energy resolution, and recombination fluctuations in liquid xenon

Abstract

This work presents an analysis of monoenergetic electronic recoil peaks in the dark-matter-search and calibration data from the first underground science run of the Large Underground Xenon (LUX) detector. Liquid xenon charge and light yields for electronic recoil energies between 5.2 and 661.7 keV are measured, as well as the energy resolution for the LUX detector at those same energies. Additionally, there is an interpretation of existing measurements and descriptions of electron-ion recombination fluctuations in liquid xenon as limiting cases of a more general liquid xenon recombination fluctuation model. Measurements of the standard deviation of these fluctuations at monoenergetic electronic recoil peaks exhibit a linear dependence on the number of ions for energy deposits up to 661.7 keV, consistent with previous LUX measurements between 2 and 16 keV with 3H. We highlight similarities in liquid xenon recombination for electronic and nuclear recoils with a comparison of recombination fluctuations measured with low-energy calibration data

Search for annual and diurnal rate modulations in the LUX experiment

“…With the g1 and g2 corrections, the overall energy of an event can be reliably estimated as E = W ( S1c g1 + S2c g2 ), where W =13.7 eV is the average energy required to produce either one ionization electron or one scintillation photon in liquid xenon [34], and S1 c and S2 c are the positioncorrected energy variables. Throughout the LUX experiment, g1 and g2 values were regularly monitored through internal and external calibrations, including 83m Kr [32], 3 H [35], and xenon activation lines following neutron calibrations [36]. The values of g1 and g2 remained stable within WS2013, and the drift was estimated to be <8% from the beginning of WS2014-16 to the end.…”

Calibration of a two-phase xenon time projection chamber with a37Ar source

“…37 Ar can be produced through reaction 3.2a [29,30], reaction 3.2b [31,32], or reaction 3.2c [26,33,34,36]. 36 Ar(n,γ) 37 Ar (3.2a) 37 Cl(p,n) 37 Ar (3.2b) 40 Ca(n,α) 37 Ar (3.2c)…”

Relation between the Migdal Effect and Dark Matter-Electron Scattering in Isolated Atoms and Semiconductors

“…Here, P (S2|∆E nl ) = n surv e ,ne P (S2|n surv e )P (n surv e |n e )P (n e | n e ). The number of electrons escaping the interaction point n e are assumed to follow a binomial distribution, P (n e | n e ) = binom(n e |N Q , f e ) with N Q = ∆E nl /(13.8 eV) [60,61] trials and a single event probability f e = n e /N Q ; the mean number of electrons n e is either modeled following [8] or, for ∆E nl > 0.19 keV, obtained from the measured charge yield in [62]. For P (n surv e |n e ), we assume that 80% (100%) of electrons survive the drift in XENON1T/XENON100 (XENON10).…”