Expected sensitivity to galactic/solar axions and bosonic super-WIMPs based on the axio-electric effect in liquid xenon dark matter detectors

Abstract

We present systematic case studies to investigate the sensitivity of axion searches by liquid xenon detectors, using the axio-electric effect (analogue of the photoelectric effect) on xenon atoms. Liquid xenon is widely considered to be one of the best target media for detection of WIMPs (Weakly Interacting Massive Particles which may form the galactic dark matter) using nuclear recoils. Since these detectors also provide an extremely low radioactivity environment for electron recoils, very weaklyinteracting low-mass particles (< 100 keV/c 2 ), such as the hypothetical axion, could be detected as well − in this case using the axio-electric effect. Future ton-scale liquid Xe detectors will be limited in sensitivity only by irreducible neutrino background (pp-chain solar neutrino and the double beta decay of 136 Xe) in the mass range between 1 and 100 keV/c 2 . Assuming one ton-year of exposure, galactic axions (as non-relativistic dark matter) could be detected if the axio-electric coupling g Ae is greater than 10 −14 at 1 keV/c 2 axion mass (or 10 −13 at 100 keV/c 2 ). Below a few keV/c 2 , and independent of the mass, a solar axion search would be sensitive to a coupling g Ae ∼ 10 −12 . This limit will set a stringent upper bound on axion mass for the DFSZ and KSVZ models for the mass ranges m A < 0.1 eV/c 2 and < 10 eV/c 2 , respectively. Vector-boson dark matter could also be detected for a coupling constant α /α > 10 −33 (for mass 1 keV/c 2 ) or > 10 −27 (for mass 100 keV/c 2 ).

Cosmological constraints on very dark photons

“…As discussed in [3], for m V ∼ 100 keV, indirect constraints still allow this cosmological abundance with κ ∼ 10 −11 , but photoelectric absorption in dark matter detectors would leave a detectable ionization signal. The electronic background data from XENON100 in the 1-100 keV range [29] indicated no signal, thus appearing to close this window, as discussed in more detail in [30]. Very recently, these limits have also been improved by XMASS [31].…”

The 11 years solar cycle as the manifestation of the dark Universe

“…But, interestingly, most derived findings there, e.g., the planetary alignment(s) and period(s) of appearance, can be borrowed actually unmodified to corroborate the alternative scenario based on gravitational focusing of streaming constituents from the dark sector. The plethora of candidates like slow moving massive exotica, from axions and axion-like particles [12][13][14][15] to D-particles defects [16], which have been already discussed, are inspiring and may provide the energy input for the present solution of the 11 years solar clock. Then, Wolf's suggestion was advanced for his time, since both, gravitational lensing and dark matter, were unknown.…”

Light Dark Matter Search with Ionization Signals in XENON1T

“…where the top row corresponds to dark photons [39] and the bottom to axionlike particles [40]. Here σ pe is xenon's photoelectric cross section at E χ in barn, A xenon's mean atomic mass number, κ the dark photon-photon kinetic mixing parameter, and g ae the axioelectric coupling constant.…”