Axion searches with the EDELWEISS-II experiment

Abstract

Abstract. We present new constraints on the couplings of axions and more generic axionlike particles using data from the EDELWEISS-II experiment. The EDELWEISS experiment, located at the Underground Laboratory of Modane, primarily aims at the direct detection of WIMPs using germanium bolometers. It is also sensitive to the low-energy electron recoils that would be induced by solar or dark matter axions. Using a total exposure of up to 448 kg.d, we searched for axion-induced electron recoils down to 2.5 keV within four scenarios involving different hypotheses on the origin and couplings of axions. We set a 95 % CL limit on the coupling to photons g Aγ < 2.13 × 10 −9 GeV −1 in a mass range not fully covered by axion helioscopes. We also constrain the coupling to electrons, g Ae < 2.56 × 10 −11 , similar to the more indirect solar neutrino bound. Finally we place a limit on g Ae × g eff AN < 4.70 × 10 −17 , where g eff AN is the effective axion-nucleon coupling for 57 Fe. Combining these results we fully exclude the mass range 0.91 eV < m A < 80 keV for DFSZ axions and 5.73 eV < m A < 40 keV for KSVZ axions.

Searching for dark absorption with direct detection experiments

“…The case of absorption in bound electrons, known as the axioelectric effect, has been originally suggested in [17,18]. Numerous direct-detection experiments have conducted searches assuming that the ALP constitutes the galactic DM or is produced in the Sun, including CoGeNT [19], CDMS [20], EDEL-WEISS [21], XENON100 [22], and KIMS [23]. Here we show that other existing data can improve on these bounds and provide projections for future experiments.…”

“…Shaded gray regions show known constraints from anomalous cooling of the Sun, red giant stars (RG), white dwarf stars (WD), and/or horizontal branch stars (HB), which are independent of the ALP or A relic density. Also shown (left) are the combined bounds from XENON100 [22], EDELWEISS [21], CDMS [20], and CoGeNT [19]; and (right) a bound derived in [35] based on XENON100 data from 2014 [22]. Shaded orange region in left plot is consistent with an ALP possibly explaining the white dwarf luminosity function.…”

Search for solar axions with CsI(Tl) crystal detectors

“…as shown in figure 6. The dotted lines are limits by XMASS [35], EDELWEISS-II [36], XENON100 [37] and Si(Li) [38] experiments. The dash-dotted line shows indirect astrophysical bounds, solar neutrino [39] and red giants [40].…”

Neutrino lines from majoron dark matter

“…For m J < 10 keV, the best limits then come from astrophysics and imply 5) from the electron [97] and nucleon coupling [98], respectively. For m J up to 100 keV one has (slightly weaker) direct-detection bounds on g P Jee from EDELWEISS [99], XENON [100], XMASS [101], and MAJORANA [102], assuming J to be DM; this gives |K ee −K µµ −K τ τ | 10 −4 [101] for m J = 100 keV, roughly ten orders of magnitude weaker than the bound at m J = O(1) MeV (figure 5). The couplings to quarks are much less constrained for m J > 10 keV; since there are no flavor-changing processes in the quark sector mediated by the majoron at the one-loop level, quark-flavor constraints are suppressed.…”