Limit on Invisible ${{\mathit A}^{0}}$ (Axion) Electron Coupling

INSPIRE   PDGID:
S029AEC
The limit is for $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$ $\phi _{A}{{\overline{\mathit e}}}(\mathit i$ $\gamma _{5}){{\mathit e}}$, or equivalently, the dipole-dipole potential $−{\mathit g{}^{2}_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}\over 16{{\mathit \pi}} {{\mathit m}^{2}}_{{{\mathit e}}}}$ (($\mathbf {\sigma }_{1}\cdot{}\mathbf {\sigma }_{2}$) $-3(\mathbf {\sigma }_{1}\cdot{}\mathbf {\mathit n}$) ($\mathbf {\sigma }_{2}\cdot{}\mathbf {\mathit n}))/\mathit r{}^{3}$ where $\mathbf {\mathit n}=\mathbf {\mathit r}/\mathit r$ and the sign of the potential was corrected based on DAIDO 2017.

VALUE CL% DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
$<2.35 \times 10^{-12}$ 90 1
AALBERS
2023A
LZ Solar axions
$<1.3 \times 10^{-14}$ 90 2
AALBERS
2023A
LZ ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 17$ keV
$<1.61 \times 10^{-11}$ 90 3
ADHIKARI
2023
C100 Solar axions
$<6 \times 10^{-13}$ 90 4
ADHIKARI
2023A
C100 ${\mathit m}_{{{\mathit A}^{0}}}$ =$10 - 1000$ keV
$<8 \times 10^{-14}$ 90 5
AGNES
2023A
DS50 ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.03 - 20$ keV
6
APRILE
2023B
XE1T Neutron star merger
$<3 \times 10^{-9}$ 95 7
CAPOZZI
2023A
DUMP ${\mathit m}_{{{\mathit A}^{0}}}$ = $10^{4} - 2 \times 10^{7}$ eV
$<6 \times 10^{-15}$ 8
WADEKAR
2023
ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = 100 keV
$<4 \times 10^{-12}$ 90 9
APRILE
2022
XE1T ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.01 - 0.4$ keV
$<9 \times 10^{-15}$ 90 10
APRILE
2022B
XENT ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 39$, $44 - 140$ keV
$<2 \times 10^{-12}$ 90 11
APRILE
2022B
XENT Solar axions
12
DESSERT
2022
ASTR Magnetic white dwarf
$<2.6 \times 10^{-6}$ 95 13
IKEDA
2022
${\mathit m}_{{{\mathit A}^{0}}}=33.117 - 33.130$ $\mu $eV
$<2.5 \times 10^{-18}$ 14
LANGHOFF
2022
COSM ${\mathit m}_{{{\mathit A}^{0}}}$ = $20 - 3 \times 10^{4}$ keV
15
WANG
2022C
${\mathit m}_{{{\mathit A}^{0}}}{}\leq{}$ 0.47 meV
16
XIAO
2022
ASTR Betelgeuse
17
CALORE
2021
ASTR Core-collapse SNe
$<2.5 \times 10^{-10}$ 18
LUCENTE
2021
ASTR SN 1987A
$<5.1 \times 10^{-12}$ 90 19
AGOSTINI
2020
HPGE ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.06 - 1$ MeV
$<1 \times 10^{-9}$ 90 20
AMARAL
2020
SCDM ${\mathit m}_{{{\mathit A}^{0}}}$ = $1.2 - 50$ eV
$<2 \times 10^{-14}$ 90 21
APRILE
2020
XE1T ${\mathit m}_{{{\mathit A}^{0}}}$ = 1 keV
$2.6 - 3.7 \times 10^{-12}$ 90 22
APRILE
2020
XE1T Solar axions
$<6 \times 10^{-13}$ 90 23
ARALIS
2020
SCDM ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.04 - 500$ keV
$<1.3 \times 10^{-13}$ 95 24
CAPOZZI
2020
ASTR Tip of the Red Giant Branch
$<1.7 \times 10^{-11}$ 95 25
CRESCINI
2020
QUAX ${\mathit m}_{{{\mathit A}^{0}}}$ = $42.4 - 43.1$ $\mu $eV
$<1.8 \times 10^{-9}$ 26
GHOSH
2020A
COSM ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ 0.5 MeV
$<1.48 \times 10^{-13}$ 95 27
STRANIERO
2020
ASTR Tip of the Red Giant Branch
$<2.48 \times 10^{-11}$ 90 28
WANG
2020A
CDEX Solar axions
$<4 \times 10^{-13}$ 90 29
WANG
2020A
CDEX ${\mathit m}_{{{\mathit A}^{0}}}$ = 1.5 keV
$<1.7 \times 10^{-11}$ 90 30
ADHIKARI
2019B
C100 Solar axions
$<2.3 \times 10^{-14}$ 90 31
APRILE
2019D
XE1T ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.186 - 1$ keV
32
DESSERT
2019
ASTR Magnetic white dwarf
$<2.6 \times 10^{-10}$ 95 33
TERRANO
2019
Torsion pendulum
$<1.5 \times 10^{-13}$ 90 34
ABE
2018F
XMAS ${\mathit m}_{{{\mathit A}^{0}}}$ = $40 - 120$ keV
$<1.1 \times 10^{-11}$ 90 35
ARMENGAUD
2018
EDE3 Solar axions
$<4 \times 10^{-13}$ 90 36
ARMENGAUD
2018
EDE3 ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.8 - 500$ keV
$<4.9 \times 10^{-10}$ 95 37
CRESCINI
2018
QUAX ${\mathit m}_{{{\mathit A}^{0}}}$ = 58 $\mu $eV
38
FICEK
2018
THEO ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 10 keV
$<4.5 \times 10^{-13}$ 90 39
ABGRALL
2017
HPGE ${\mathit m}_{{{\mathit A}^{0}}}$ = 11.8 keV
$<3.5 \times 10^{-12}$ 90 40
AKERIB
2017B
LUX Solar axions
$<4.2 \times 10^{-13}$ 90 41
AKERIB
2017B
LUX ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 16$ keV
$<2.3 \times 10^{-13}$ 90 42
APRILE
2017B
X100 ${\mathit m}_{{{\mathit A}^{0}}}$ = 6 keV
$<4 \times 10^{-4}$ 90 43
FICEK
2017
THEO ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 1 keV
$<4.35 \times 10^{-12}$ 90 44
FU
2017A
PNDX Solar axions
$<4.3 \times 10^{-14}$ 90 45
FU
2017A
PNDX ${\mathit m}_{{{\mathit A}^{0}}}$ = 2 keV
$<5 \times 10^{-13}$ 90 46
LIU
2017A
CDEX ${\mathit m}_{{{\mathit A}^{0}}}$ = 13 keV
$<2.5 \times 10^{-11}$ 90 47
LIU
2017A
CDEX Solar axions
$<0.15$ 95 48
LUO
2017
${\mathit m}_{{{\mathit A}^{0}}}$ = 300 eV
$<3.3 \times 10^{-13}$ 68 49
BATTICH
2016
ASTR White dwarf cooling
$<7 \times 10^{-13}$ 50
CORSICO
2016
ASTR White dwarf cooling
$<1.39 \times 10^{-11}$ 90 51
YOON
2016
KIMS Solar axions
$<7.4 \times 10^{-9}$ 95 52
TERRANO
2015
${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 30 $\mu $eV
$<8 \times 10^{-13}$ 90 53
ABE
2014F
XMAS ${\mathit m}_{{{\mathit A}^{0}}}$ = 60 keV
$<7.7 \times 10^{-12}$ 90 54
APRILE
2014B
X100 Solar axions
55
APRILE
2014B
X100 ${\mathit m}_{{{\mathit A}^{0}}}$ = $5 - 7$ keV
$< 0.96 - 8.2 \times 10^{-8}$ 90 56
DERBIN
2014
CNTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.1 - 1$ MeV
$<2.8 \times 10^{-13}$ 99 57
MILLER-BERTOL..
2014
ASTR White dwarf cooling
$<5.4 \times 10^{-11}$ 90 58
ABE
2013D
XMAS Solar axions
$<1.07 \times 10^{-12}$ 90 59
ARMENGAUD
2013
EDEL ${\mathit m}_{{{\mathit A}^{0}}}$ = 12.5 keV
$<2.59 \times 10^{-11}$ 90 60
ARMENGAUD
2013
EDEL Solar axions
61
BARTH
2013
CAST Solar axions
$< 1.4 - 9.7 \times 10^{-7}$ 90 62
DERBIN
2013
CNTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.1 - 1$ MeV
$<1.5 \times 10^{-8}$ 68 63
HECKEL
2013
${\mathit m}_{{{\mathit A}^{0}}}{}\leq{}$ 0.1 $\mu $eV
$<4.3 \times 10^{-13}$ 95 64
VIAUX
2013A
ASTR Low-mass red giants
$<7 \times 10^{-13}$ 95 65
CORSICO
2012
ASTR White dwarf cooling
$<2.2 \times 10^{-10}$ 90 66
DERBIN
2012
CNTR Solar axions
$<0.02 - 1 \times 10^{-10}$ 90 67
AALSETH
2011
CNTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.3 - 8$ keV
$<1.4 \times 10^{-12}$ 90 68
AHMED
2009A
CDMS ${\mathit m}_{{{\mathit A}^{0}}}$ = 2.5 keV
$<4 \times 10^{-9}$ 69
DAVOUDIASL
2009
ASTR Earth cooling
$<2.7 \times 10^{-8}$ 66 70
NI
1994
Induced magnetism
70
CHUI
1993
Induced magnetism
$<3.6 \times 10^{-7}$ 66 71
PAN
1992
Torsion pendulum
$<2.9 \times 10^{-8}$ 95 70
BOBRAKOV
1991
Induced magnetism
$<1.9 \times 10^{-6}$ 66 72
WINELAND
1991
NMR
$<7 \times 10^{-7}$ 66 71
RITTER
1990
Torsion pendulum
$<6.6 \times 10^{-8}$ 95 70
VOROBYOV
1988
Induced magnetism
1  AALBERS 2023A look for solar axions from the ABC processes. See their Fig. 6 for the limits.
2  AALBERS 2023A look for absorption of axion dark matter. The quoted limit is for ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ 1.4 keV. The local density ${{\mathit \rho}_{{{A}}}}$ = 0.3 GeV/cm${}^{3}$ is assumed. See their Fig. 7 for mass-dependent limits.
3  ADHIKARI 2023 is an update of ADHIKARI 2019B.
4  ADHIKARI 2023A look for absorption and Compton-like processes of axion dark matter. The quoted limit is for ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ 37 keV. See their Fig. 4 for mass-dependent limits.
5  AGNES 2023A look for absorption of axion dark matter. The quoted limit is for ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ 0.25 keV. The local density ${{\mathit \rho}_{{{A}}}}$ = 0.3 GeV/cm${}^{3}$ is assumed. See their Fig. 2 for mass-dependent limits.
6  APRILE 2023B look for an absorption signal of axions within $\pm500$ seconds of the GW signals, including the neutron star merger GW170817. They set a 90$\%$ CL upper limit on the product of coincident fluence and cross section of axions to be less than $10^{-29}$ cm${}^{2}$/cm${}^{2}$ in the recoil energy range of $5.5 - 210$ keV$_{ee}$.
7  CAPOZZI 2023A search for axions produced in electromagnetic showers in proton beam dumps and fixed target experiments. In this case, they reinterpret MiniBoone data. Quoted limit applies at 1 MeV. See Fig. 8 for mass-dependent limits.
8  WADEKAR 2023 use the Leo T dwarf galaxy's interstellar medium to derive limits, requiring the heating rate from axion dark matter absorption into hydrogen atoms and two-photon decay to be less than the astrophysical cooling rate. See Fig. 2 for limits over ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 100$ keV, which loosen for lighter masses.
9  APRILE 2022 extend APRILE 2019D to lower masses by removing the background of ionization signals correlated with high-energy events. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = 0.1 keV. See their Fig. 15 for mass-dependent limits.
10  APRILE 2022B is an update of APRILE 2020, and set the limit, $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}{ {}\lesssim{} }$ $9 \times 10^{-15} - 3 \times 10^{-13}$. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = 2 keV. They exclude the XENON1T excess found in APRILE 2020. See their Fig. 6 for mass-dependent limits.
11  APRILE 2022B is an update of APRILE 2020. They exclude the XENON1T excess found in APRILE 2020. The quoted limit holds for small $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$. See their Fig. 6 for correlation between $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$ and $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ .
12  DESSERT 2022 is an update of DESSERT 2019. They used the Chandra observation of the magnetic white dwarf RE J0317-853 to look for converted X-rays in the magnetosphere from axions produced in the core through electron bremsstrahlung. They obtained the limit, $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}\cdot{}\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ $<$ $1.3 \times 10^{-25}$ GeV${}^{-1}$ at 95$\%$ CL for ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ $10^{-5}$ eV. See their Fig. 1 for mass-dependent limits.
13  IKEDA 2022 look for magnons excited by dark matter axions, using data taken with a hybrid quantum system consisting of a superconducting qubit and a spherical ferrimagnetic crystal. The quoted limit assumes the local dark matter density ${{\mathit \rho}_{{{A}}}}$ = 0.45 GeV/cm${}^{3}$ and the velocity $\mathit v$ = 220 km/sec. See their Fig. 4 for the limits.
14  LANGHOFF 2022 set limits by considering the freeze-in production of axions coupled to electrons without anomalous coupling to photons. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = 15 MeV for the reheating temperature equal to 5 MeV. See their Fig. 2 for mass-dependent limits.
15  WANG 2022C use the spin-amplifier based on hyperpolarized ${}^{129}\mathrm {Xe}$ to set limits on the product of the axion couplings to electrons and nucleons as $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$ $\mathit g_{{{\mathit A}} {{\mathit n}} {{\mathit n}}}$ $<$ $4 \times 10^{2}$ (95 $\%$ CL) at ${\mathit m}_{{{\mathit A}^{0}}}$ = 0.1 meV. Here $\mathit g_{{{\mathit A}} {{\mathit n}} {{\mathit n}}}$ is the dimensionless axion-neutron coupling. See their Fig. 4 for the mass-dependent limits.
16  XIAO 2022 extend XIAO 2021 in the list of photon coupling limits by including the production of axions from Compton and bremsstrahlung processes, and set limits on the product of the axion couplings to electrons and photons as $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$ $<$ $0.4 - 2.8 \times 10^{-24}$ GeV${}^{-1}$ (95 $\%$ CL) for ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $3.5 \times 10^{-11}$eV. See their Fig. 5 for the limits. They are comparable to those of DESSERT 2019 and more restrictive than the CAST bounds of BARTH 2013.
17  CALORE 2021 consider the production of axions from Galactic and extragalactic SNe via nucleon-nucleon bremsstrahlung and their subsequent decay into electron-positron pairs, and exclude the range of $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$ $\simeq{}$ $10^{-19} - 10^{-11}$ at $\mathit g_{{{\mathit A}} {{\mathit p}} {{\mathit p}}}$ = $10^{-9}$ for ${\mathit m}_{{{\mathit A}^{0}}}$ = $3 - 30$ MeV. See their Fig. 7 for the limits.
18  LUCENTE 2021 study the axion production in a supernova via electron-proton bremsstrahlung and electron-positron fusion, and exclude the range of $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$ $\simeq{}$ $10^{-10} - 10^{-8}$ for ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 160$ MeV. The quoted limit is at ${\mathit m}_{{{\mathit A}^{0}}}$ = 120 MeV. See their Fig. 12 for the mass-dependent limits.
19  AGOSTINI 2020 is analogous to AHMED 2009A. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = 150 keV. Their limits in their Fig. 3 were later found to be incorrect due to an error of their Eqs. (1) and (2). See Fig. 3 in AGOSTINI 2022A for the corrected limits.
20  AMARAL 2020 use a second-generation SuperCDMS high-voltage eV-resolution detector to set limits on dark-matter axion absorption. The quoted limit is for ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ 17 eV. The local density ${{\mathit \rho}_{{{A}}}}$ = 0.3 GeV/cm${}^{3}$ is assumed. See their Fig. 3 for mass-dependent limits.
21  APRILE 2020 is an update of APRILE 2017B where they look for an absorption signal of axion dark matter. They obtained the limit, $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$ ${ {}\lesssim{} }$ $2 \times 10^{-14} - 1 \times 10^{-12}$ at 90$\%$CL for ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 200$ keV. They also found an excess over known backgrounds, which favors the mass ${\mathit m}_{{{\mathit A}^{0}}}$ = $2.3$ $\pm0.2$ keV with a 3 $\sigma $ significance. See their Fig. 10 for mass-dependent limits.
22  APRILE 2020 look for solar axions from the ABC interactions, the Primakoff conversion, and the 14.4 keV M1 transition of ${}^{57}\mathrm {Fe}$, and set limits on $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}} }$, $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$, $\mathit g_{{{\mathit A}} {{\mathit N}} {{\mathit N}}}$, and their products. An excess is observed at low energies between 2 and 3 keV. See their Fig.8 for correlation between the couplings. The quoted limit applies to the case of vanishing $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ and $\mathit g_{{{\mathit A}} {{\mathit N}} {{\mathit N}}}$.
23  ARALIS 2020 is analogous to AHMED 2009A. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = 0.3 keV. The limits at masses above 3 keV in their Fig. 9 was later found to be incorrect due to an error in their analysis. See Fig. 2 in ARALIS 2021 for the corrected limits.
24  CAPOZZI 2020 obtains a limit on the axion-electron coupling from the brightness of the tip of the red-giant branch in $\omega $ Centauri. A similar limit of $<$ $1.6 \times 10^{-13}$ is obtained in NGC 4258.
25  CRESCINI 2020 is an update of CRESCINI 2018. They assume a local axion dark matter density, ${{\mathit \rho}_{{{A}}}}$ = 0.3 GeV/cm${}^{3}$. See their Fig.4 for the limits.
26  GHOSH 2020A study thermal production of axion via coupling to leptons in the early universe and estimate its contribution to $\Delta \mathit N_{{\mathrm {eff}}}$. The quoted limit is for $\Delta \mathit N_{{\mathrm {eff}}}$ $<$ 0.5. See their Fig. 7 for their mass-dependent limits.
27  STRANIERO 2020 is analogous to CAPOZZI 2020, with 22 galactic globular clusters used to derive the limit.
28  WANG 2020A is an update of LIU 2017A. See their Fig. 9.
29  WANG 2020A is an update of LIU 2017A. They assume a local axion dark matter density, ${{\mathit \rho}_{{{A}}}}$ = 0.3 GeV/cm${}^{3}$. See their Fig. 10 for limits between 0.185 $<$ ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 10 keV.
30  ADHIKARI 2019B is analogous to LIU 2017A.
31  APRILE 2019D is analogous to APRILE 2017B, but they use only ionization signals. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = 0.7 keV. See their Fig. 5(e) for mass-dependent limits.
32  DESSERT 2019 used the Suzaku observations of a magnetic white dwarf (RE J0317-853) to look for X-ray signatures converted from axions in the surrounding magnetic fields. They obtained the limit, $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}\cdot{}\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ $<$ $1.6 \times 10^{-24}$ GeV${}^{-1}$ at 95$\%$CL for ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ $10^{-5}$ eV. See their Fig. 2 for mass-dependent limits.
33  TERRANO 2019 look for the axion-induced oscillating magnetic field acting on the electron spin, using data taken with a rotating torsion pendulum containing polarized electrons. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = $10^{-23} - 10^{-18}$ eV and assumes a local axion dark matter density, ${{\mathit \rho}_{{{A}}}}$ = 0.45 GeV/cm${}^{3}$. See their Fig. 5 for mass-dependent limits.
34  ABE 2018F is an update of ABE 2014F. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = 60 keV. See their Fig. 5 for mass-dependent limits.
35  ARMENGAUD 2018 is analogous to LIU 2017A.
36  ARMENGAUD 2018 is analogous to AHMED 2009A. See the left panel of Fig. 5 for mass-dependent limits.
37  CRESCINI 2018 look for collective excitations of the electron spins caused by dark matter axions. The quoted limit assumes the local dark matter density, ${{\mathit \rho}_{{{A}}}}$ = 0.45 GeV/cm${}^{3}$.
38  FICEK 2018 use the measurements of the hyperfine structure of antiprotonic helium to constrain a dipole-dipole potential between electron and antiproton. See their Fig. 3 for limits on various spin- and velocity-dependent potentials.
39  ABGRALL 2017 is analogous to AHMED 2009A using the MAJORANA DEMONSTRATOR. See their Fig. 2 for limits between 6 keV $<$ ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 97 keV.
40  AKERIB 2017B is analogous to LIU 2017A.
41  AKERIB 2017B is analogous to AHMED 2009A. See their Fig. 7 for mass-dependent limits.
42  APRILE 2017B is analogous to AHMED 2009A. They found a bug in their code and needed to correct the limits in Fig. 7 of APRILE 2014B. See their Fig. 1 for the corrected limits between 1 keV $<$ ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 40 keV.
43  FICEK 2017 look for spin-dependent interactions between electrons by comparing precision spectroscopic measurements in ${}^{4}\mathrm {He}$ with theoretical calculations. See their Fig. 1 for limits up to ${\mathit m}_{{{\mathit A}^{0}}}$ = 10 keV.
44  FU 2017A is analogous to LIU 2017A. See their Fig. 3 for mass-dependent limits.
45  FU 2017A is analogous to AHMED 2009A. See their Fig. 4 for mass-dependent limits.
46  LIU 2017A is analogous to AHMED 2009A. See their Fig. 9 for limits between 0.25 keV $<$ ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 20 keV.
47  LIU 2017A look for solar axions produced from Compton, bremsstrahlung, atomic-recombination and deexcitation channels, and set a limit for ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 1 keV.
48  LUO 2017 use a recent measurement of the dipole-dipole interaction between two iron atoms at the nanometer scale and set a limit for ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 1 keV. See their Fig. 3 for mass-dependent limits.
49  BATTICH 2016 is analogous to CORSICO 2016 and used the pulsating DB white dwarf PG 1351+489.
50  CORSICO 2016 studied the cooling rate of the pulsating DA white dwarf L19-2 based on an asteroseismic model.
51  YOON 2016 look for solar axions with the axio-electric effect in ${}^{}\mathrm {CsI}({}^{}\mathrm {Tl}$) crystals and set a limit for ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 1 keV.
52  TERRANO 2015 used a torsion pendulum and rotating attractor with 20-pole electron-spin distributions. See their Fig. 4 for a mass-dependent limit up to ${\mathit m}_{{{\mathit A}^{0}}}$ = 500 $\mu $eV.
53  ABE 2014F set limits on the axioelectric effect in the XMASS detector assuming the pseudoscalar constitutes all the local dark matter. See their Fig. 3 for limits between ${\mathit m}_{{{\mathit A}^{0}}}$ = $40 - 120$ keV.
54  APRILE 2014B look for solar axions using the XENON100 detector.
55  APRILE 2014B is analogous to AHMED 2009A. Their Fig. 7 was later found to be incorrect due to a bug in their code. See Fig. 1 in APRILE 2017B for the corrected limits.
56  DERBIN 2014 is an update of DERBIN 2013 with a BGO scintillating bolometer. See their Fig. 3 for mass-dependent limits.
57  MILLER-BERTOLAMI 2014 studied the impact of axion emission on white dwarf cooling in a self-consistent way.
58  ABE 2013D is analogous to DERBIN 2012, using the XMASS detector.
59  ARMENGAUD 2013 is similar to AALSETH 2011. See their Fig. 10 for limits between 3 keV $<$ ${\mathit m}_{{{\mathit A}^{0}}}<$ 100 keV.
60  ARMENGAUD 2013 is similar to DERBIN 2012, and take account of axio-recombination and axio-deexcitation effects. See their Fig. 12 for mass-dependent limits.
61  BARTH 2013 search for solar axions produced by axion-electron coupling, and obtained the limit, $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}\cdot{}\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}<$ $8.1 \times 10^{-23}$ GeV${}^{-1}$ at 95$\%$CL.
62  DERBIN 2013 looked for 5.5 MeV solar axions produced in ${{\mathit p}}$ ${{\mathit d}}$ $\rightarrow{}^{3}\mathrm {He}{{\mathit A}^{0}}$ in a BGO detector through the axioelectric effect. See their Fig. 4 for mass-dependent limits.
63  HECKEL 2013 studied the influence of 2 or 4 stationary sources each containing $6.0 \times 10^{24}$ polarized electrons, on a rotating torsion pendulum containing $9.8 \times 10^{24}$ polarized electrons. See their Fig. 4 for mass-dependent limits.
64  VIAUX 2013A constrain axion emission using the observed brightness of the tip of the red-giant branch in the globular cluster M5.
65  CORSICO 2012 attributed the excessive cooling rate of the pulsating white dwarf R548 to emission of axions with $\mathit g_{{{\mathit A}}{{\mathit e}}{{\mathit e}}}$ $\simeq{}$ $4.8 \times 10^{-13}$.
66  DERBIN 2012 look for solar axions with the axio-electric effect in a ${}^{}\mathrm {Si}({}^{}\mathrm {Li}$) detector. The solar production is based on Compton and bremsstrahlung processes.
67  AALSETH 2011 is analogous to AHMED 2009A. See their Fig.$~$4 for mass-dependent limits.
68  AHMED 2009A assume keV-mass pseudoscalars are the local dark matter and constrain the axio-electric effect in the CDMS detector. See their Fig.$~$5 for mass-dependent limits.
69  DAVOUDIASL 2009 use geophysical constraints on Earth cooling by axion emission.
70  These experiments measured induced magnetization of a bulk material by the spin-dependent potential generated from other bulk material with aligned electron spins, where the magnetic field is shielded with superconductor. The sign of the limit set by CHUI 1993 is opposite to that of the axion-mediated dipole-dipole potential.
71  These experiments used a torsion pendulum to measure the potential between two bulk matter objects where the spins are polarized but without a net magnetic field in either of them. The limits reflect the corrected sign of the dipole-dipole potential.
72  WINELAND 1991 looked for an effect of bulk matter with aligned electron spins on atomic hyperfine splitting using nuclear magnetic resonance.
References