# Search for Relic Invisible Axions INSPIRE search

Limits are for [$\mathit G_{ {{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}} }/{\mathit m}_{{{\mathit A}^{0}}}]{}^{2}\rho _{\mathit A}$ where $\mathit G_{ {{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}} }$ denotes the axion two-photon coupling, $\mathit L_{{\mathrm {int}}}$ = $−$ ${\mathit G_{ {{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}} }\over 4}{{\mathit \phi}_{{A}}}{{\mathit F}}_{ {{\mathit \mu}} {{\mathit \nu}} }{{\widetilde{\mathit F}}}{}^{ {{\mathit \mu}} {{\mathit \nu}} }$ = $\mathit G_{ {{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}} }\phi _{\mathit A}\mathbf {E}\cdot{}\mathbf {B}$, and $\rho _{\mathit A}$ is the axion energy density near the earth.
VALUE CL% DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
$<2.6 \times 10^{-39}$ 95 1
 2019
QUAX ${\mathit m}_{{{\mathit A}^{0}}}$ = 37.5 $\mu$eV
$<6 \times 10^{-5}$ 2
 2019
ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $10^{-21}$ eV
$<2 \times 10^{-27}$ 95 3
 2019 A
ABRA ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.31 - 8.3$ neV
$<7.3 \times 10^{-40}$ 90 4
 2018
ADMX ${\mathit m}_{{{\mathit A}^{0}}}$ = $17.38 - 17.57$ $\mu$eV
$<1.8 \times 10^{-39}$ 90 4
 2018
ADMX ${\mathit m}_{{{\mathit A}^{0}}}$ = $21.03 - 23.98$ $\mu$eV
$<3.4 \times 10^{-39}$ 90 4
 2018
ADMX ${\mathit m}_{{{\mathit A}^{0}}}$ = $29.67 - 29.79$ $\mu$eV
$<1.4 \times 10^{-44}$ 90 5
 2018
ADMX ${\mathit m}_{{{\mathit A}^{0}}}$ =$2.66 - 2.81$ $\mu$eV
$<2.87 \times 10^{-42}$ 90 6
 2018
HYST ${\mathit m}_{{{\mathit A}^{0}}}$ =$23.15 - 24$ $\mu$eV
7
 2017
AURG ${\mathit m}_{{{\mathit S}^{0}}}$ = $3.5 - 3.9$ peV
$<3 \times 10^{-42}$ 90 8
 2017
HYST ${\mathit m}_{{{\mathit A}^{0}}}$ = $23.55 - 24.0$ $\mu$eV
$<1.0 \times 10^{-29}$ 95 9
 2017
${\mathit m}_{{{\mathit A}^{0}}}$ = $24.7 - 29.1$ $\mu$eV
$<8.6 \times 10^{-42}$ 90 10
 2016
ADMX ${\mathit m}_{{{\mathit A}^{0}}}$ =$3.36 - 3.52$ or $3.55 - 3.69$ $\mu$eV
11
 2013
${\mathit m}_{{{\mathit A}^{0}}}$ = 0.11 meV
$<3.5 \times 10^{-43}$ 12
 2011
ADMX ${\mathit m}_{{{\mathit A}^{0}}}$ = $3.3 - 3.69 \times 10^{-6}$ eV
$<2.9 \times 10^{-43}$ 90 13
 2010
ADMX ${\mathit m}_{{{\mathit A}^{0}}}$ = $3.34 - 3.53$ eV
$<1.9 \times 10^{-43}$ 97.7 14
 2006
ADMX ${\mathit m}_{{{\mathit A}^{0}}}$ = $1.98 - 2.17$ eV
$<5.5 \times 10^{-43}$ 90 15
 2004
ADMX ${\mathit m}_{{{\mathit A}^{0}}}$ = $1.9 - 3.3$ eV
16
 1998
THEO
$<2 \times 10^{-41}$ 17
 1990
CNTR ${\mathit m}_{{{\mathit A}^{0}}}$ = ($5.4 - 5.9){}10^{-6}$ eV
$<6.3 \times 10^{-42}$ 95 18
 1989
CNTR ${\mathit m}_{{{\mathit A}^{0}}}$ = ($4.5 - 10.2){}10^{-6}$ eV
$<5.4 \times 10^{-41}$ 95 18
 1989
CNTR ${\mathit m}_{{{\mathit A}^{0}}}$ = ($11.3 - 16.3){}10^{-6}$ eV
1  ALESINI 2019 used a superconducting resonant cavity made of ${}^{}\mathrm {NbTi}$ to increase the quality factor. The limit applies to a mass range of 0.2 neV around ${\mathit m}_{{{\mathit A}^{0}}}$ = 37.5 $\mu$eV.
2  FUJITA 2019 look for photon birefringence under the oscillating axion background using the polarimetric imaging observation of a protoplanetary disk, AB Aur. See their Fig. 2 for a more conservative limit taking account of possible systematic effects.
3  OUELLET 2019A look for the axion-induced oscillating magnetic field generated by a toroidal magnetic field. The quoted limit applies at ${\mathit m}_{{{\mathit A}^{0}}}$ = 8 neV. See their Fig. 3 for the mass-dependent limits.
4  BOUTAN 2018 use a small high frequency cavity installed above the main ADMX cavity to look for heavier axion dark matter. See their Fig. 4 for mass-dependent limits.
5  DU 2018 is analogous to DUFFY 2006 . They upgraded a dilution refrigerator to reduce the system noise. The quoted limit is around ${\mathit m}_{{{\mathit A}^{0}}}$ = 2.69 $\mu$eV for the boosted Maxwellian axion line shape. See Fig. 4 for their mass-dependent limits.
6  ZHONG 2018 is analogous to BRUBAKER 2017 . The quoted limit applies at ${\mathit m}_{{{\mathit A}^{0}}}$ = 23.76 $\mu$eV. See Fig. 4 for their mass-dependent limits.
7  BRANCA 2017 look for modulations of the fine-structure constant and the electron mass due to moduli dark matter by using the cryogenic resonant-mass AURIGA detector. The limit on the assumed dilatonic coupling implies $\mathit G_{ {{\mathit S}} {{\mathit \gamma}} {{\mathit \gamma}} }$ $<$ $1.5 \times 10^{-24}$ GeV${}^{-1}$ for the scalar to two-photon coupling. See Fig. 5 for the mass-dependent limits.
8  BRUBAKER 2017 used a microwave cavity detector at the Yale Wright Laboratory to search for dark matter axions. See Fig. 3 for the mass-dependent limits.
9  CHOI 2017 used a microwave cavity detector with toroidal geometry. See Fig. 4 for their mass-dependent limits.
10  HOSKINS 2016 is analogous to DUFFY 2006 . See Fig.$~$12 for mass-dependent limits in terms of the local dark matter density.
11  BECK 2013 argues that dark-matter axions passing through Earth may generate a small observable signal in resonant S/N/S Josephson junctions. A measurement by HOFFMANN 2004 [Physical Review B70 180503 (2004)] is interpreted in terms of subdominant dark matter axions with ${\mathit m}_{{{\mathit A}^{0}}}$ = 0.11 meV.
12  HOSKINS 2011 is analogous to DUFFY 2006 . See Fig.$~$4 for the mass-dependent limit in terms of the local density.
13  ASZTALOS 2010 used the upgraded detector of ASZTALOS 2004 to search for halo axions. See their Fig.$~$5 for the ${\mathit m}_{{{\mathit A}^{0}}}$ dependence of the limit.
14  DUFFY 2006 used the upgraded detector of ASZTALOS 2004 , while assuming a smaller velocity dispersion than the isothermal model as in Eq. (8) of their paper. See Fig. 10 of their paper on the axion mass dependence of the limit.
15  ASZTALOS 2004 looked for a conversion of halo axions to microwave photons in magnetic field. At 90$\%$ CL, the KSVZ axion cannot have a local halo density more than 0.45~GeV/cm${}^{3}$ in the quoted mass range. See Fig.~7 of their paper on the axion mass dependence of the limit.
16  KIM 1998 calculated the axion-to-photon couplings for various axion models and compared them to the HAGMANN 1990 bounds. This analysis demonstrates a strong model dependence of $\mathit G_{ {{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}} }$ and hence the bound from relic axion search.
17  HAGMANN 1990 experiment is based on the proposal of SIKIVIE 1983 .
18  WUENSCH 1989 looks for condensed axions near the earth that could be converted to photons in the presence of an intense electromagnetic field via the Primakoff effect, following the proposal of SIKIVIE 1983 . The theoretical prediction with [$\mathit G_{ {{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}} }/{\mathit m}_{{{\mathit A}^{0}}}]{}^{2}$ = $2 \times 10^{-14}$ MeV${}^{-4}$ (the three generation DFSZ model) and $\rho _{\mathit A}$ = 300 MeV/cm${}^{3}$ that makes up galactic halos gives ($\mathit G_{ {{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}} }/{\mathit m}_{{{\mathit A}^{0}}}){}^{2}$ $\rho _{\mathit A}$ = $4 \times 10^{-44}$. Note that our definition of $\mathit G_{ {{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}} }$ is (1/4$\pi$) smaller than that of WUENSCH 1989 .
References:
 ALESINI 2019
PR D99 101101 Galactic axions search with a superconducting resonant cavity
 FUJITA 2019
PRL 122 191101 Hunting Axion Dark Matter with Protoplanetary Disk Polarimetry
 OUELLET 2019A
PRL 122 121802 First Results from ABRACADABRA-10 cm: A Search for Sub-$\\mu$eV Axion Dark Matter
 BOUTAN 2018
PRL 121 261302 Piezoelectrically Tuned Multimode Cavity Search for Axion Dark Matter
 DU 2018
PRL 120 151301 A Search for Invisible Axion Dark Matter with the Axion Dark Matter Experiment
 ZHONG 2018
PR D97 092001 Results from phase 1 of the HAYSTAC microwave cavity axion experiment
 BRANCA 2017
PRL 118 021302 Search for Light Scalar Dark Matter Candidate with AURIGA Detector
 BRUBAKER 2017
PRL 118 061302 First Results from a Microwave Cavity Axion Search at 24 Micro-eV
 CHOI 2017
PR D96 061102 First Axion Dark Matter Search with Toroidal Geometry
 HOSKINS 2016
PR D94 082001 Modulation Sensitive Search for Nonvirialized Dark-Matter Axions
 BECK 2013
PRL 111 231801 Possible Resonance Effect of Axionic Dark Matter in Josephson Junctions
 HOSKINS 2011
PR D84 121302 Search for Nonvirialized Axionic Dark Matter
 ASZTALOS 2010
PRL 104 041301 A SQUID-Based Microwave Cavity Search for Dark-Matter Axions
 DUFFY 2006
PR D74 012006 High Resolution Search for Dark-Matter Axions
 ASZTALOS 2004
PR D69 011101 An Improved RF Cavity Search for Halo Axions
 KIM 1998
PR D58 055006 Constraints on Very Light Axions from Cavity Experiments
 HAGMANN 1990
PR D42 1297 Results from a Search for Cosmic Axions
 WUENSCH 1989
PR D40 3153 Results of a Laboratory Search for Cosmic Axions and Other Weakly-Coupled Light Particles