Limits are for the modulus of the axion-two-photon coupling $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ defined by $\mathit L~=~−\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}\phi _{\mathit A}\mathbf {E}\mathbf {\cdot{}}\mathbf {B}$. For scalars ${{\mathit S}^{0}}$ the limit is on the coupling constant in $\mathit L~=~\mathit G_{{{\mathit S}} {{\mathit \gamma}} {{\mathit \gamma}}}\phi _{S}(\mathbf {E}{}^{2}−\mathbf {B}{}^{2}$). The relation between $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ and ${\mathit m}_{{{\mathit A}^{0}}}$ is not used unless stated otherwise, i.e., many of these bounds apply to low-mass axion-like particles (ALPs), not to QCD axions.

VALUE (GeV${}^{-1}$) CL% DOCUMENT ID TECN  COMMENT • • We do not use the following data for averages, fits, limits, etc. • • $<1 \times 10^{-4}$ 90 1 ABRAHAM 2025   FASR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 74 MeV $<1 \times 10^{-10}$ 80 2 ADAMS 2025 C   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $2 \times 10^{-7} - 4 \times 10^{-7}$ eV $<9 \times 10^{-11}$ 95 3 ALTENMULLER 2025   CAST ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ 0.02 eV $<6 \times 10^{-13}$ 95 4 CANDON 2025   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $10 - 700$ keV $<6.5 \times 10^{-13}$ 95 5 CHEN 2025   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.2 - 10$ keV $<4.33 \times 10^{-11}$ 95 6 CHEN 2025 A   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $10^{-6}$ eV $<3.6 \times 10^{-11}$ 95 7 CHEN 2025 B   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $4.4 \times 10^{-10}$ $−$ $1.3 \times 10^{-8}$ eV $<1 \times 10^{-18}$ 95 8 FONG 2025   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $1.78 - 18.0$ keV $<2 \times 10^{-12}$ 95 9 GOLDSTEIN 2025   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $2 \times 10^{-13} - 3 \times 10^{-12}$ eV $<8 \times 10^{-5}$ 95 10 HAYRAPETYAN 2025 Z   CMS ${\mathit m}_{{{\mathit A}^{0}}}$ = $5 - 100$ GeV $<1.3 \times 10^{-11}$ 95 11 JANISH 2025   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.8 - 2.5$ eV $<3 \times 10^{-14}$ 95 12 KAR 2025   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $8 - 20$ eV $<4 \times 10^{-7}$ 95 13 KIRITA 2025   SAPH ${\mathit m}_{{{\mathit A}^{0}}}$ = $3 \times 10^{-3} - 0.5$ eV $<1.1 \times 10^{-12}$ 95 14 LI 2025 D   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $4 \times 10^{-10} - 1 \times 10^{-8}$ eV $<1 \times 10^{-5}$ 90 15 MIRZAKHANI 2025   MINR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $10^{7}$ eV $<6 \times 10^{-13}$ 95 16 NING 2025   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $10^{-9}$ eV $<6.24 \times 10^{-6}$ 95 17 PARK 2025   NEON ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 7 MeV $<7.3 \times 10^{-12}$ 95 18 RUZ 2025   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $4 \times 10^{-7}$ eV $<2 \times 10^{-13}$ 95 19 TODARELLO 2025   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $14.4 - 22.2$ eV ($6.5$ ${}^{+1.1}_{-1.3}$) $ \times 10^{-11}$ 20 TROITSKY 2025   ASTR ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ 10 keV $<2 \times 10^{-11}$ 95 21 YIN 2025   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $1.8 - 2.7$ eV $<5.6 \times 10^{-10}$ 90 22 ZENG 2025   PNDX ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ keV $<2.2 \times 10^{-4}$ 95 23 ABLIKIM 2024 AD   BES3 ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.18 - 2.85$ GeV $<5.8 \times 10^{-11}$ 95 24 ALTENMULLER 2024   CAST ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 0.02 eV $<7 \times 10^{-12}$ 95 25 DEV 2024   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.01 - 100$ MeV $<5 \times 10^{-11}$ 26 DIAMOND 2024   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 300$ MeV $<1.38 \times 10^{-10}$ 95 27 FORDHAM 2024   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ keV $<2 \times 10^{-11}$ 95 28 GAO 2024   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $10^{-9} - 10^{-7}$ eV $<2 \times 10^{-11}$ 95 29 GAO 2024 A   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $10^{-10} - 2 \times 10^{-7}$ eV $<4 \times 10^{-9}$ 95 30 GUO 2024   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $4.15 - 6.06$ or $8.3 - 12.2$ $\mu $eV $<1.5 \times 10^{-11}$ 95 31 LI 2024 A   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $5 \times 10^{-10} - 1 \times 10^{-7}$ eV $<7.5 \times 10^{-11}$ 95 32 LI 2024 B   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $2 \times 10^{-8} - 2 \times 10^{-6}$ eV $<4 \times 10^{-12}$ 99 33 LI 2024 D   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $10^{-9} - 10^{-8}$ eV $<3 \times 10^{-12}$ 95 34 MANZARI 2024   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 0.01 eV $<3 \times 10^{-11}$ 95 35 PANT 2024   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.3 - 1$ neV $<8 \times 10^{-4}$ 95 36 PYBUS 2024   GLUX ${\mathit m}_{{{\mathit A}^{0}}}$ = $200 - 450$ MeV $<3 \times 10^{-11}$ 95 37 RAVENSBURG 2024   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 0.5 MeV $<3 \times 10^{-13}$ 95 38 TODARELLO 2024   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $2.7 - 5.3$ eV $<1.1 \times 10^{-12}$ 39 WANG 2024 A   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $2.8 - 12.4$ eV $<5.5 \times 10^{-11}$ 95 40 BATTYE 2023   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $3.9 - 4.7$ $\mu $eV $<2 \times 10^{-13}$ 95 41 BEAUFORT 2023   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $3 - 38$ keV $<2 \times 10^{-12}$ 99 42 BERNAL 2023   COSM ${\mathit m}_{{{\mathit A}^{0}}}$ = $8 - 25$ eV $<4 \times 10^{-14}$ 99 43 CAPOZZI 2023   COSM ${\mathit m}_{{{\mathit A}^{0}}}$ = $30 - 800$ eV $<1.3 \times 10^{-7}$ 95 44 CAPOZZI 2023 A   DUMP ${\mathit m}_{{{\mathit A}^{0}}}$ = $10^{3} - 2 \times 10^{8}$ eV $<5 \times 10^{-12}$ 95 45 DAVIES 2023   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $5 - 200$ neV $<1.7 \times 10^{-10}$ 46 DIAMOND 2023   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $2 - 56$ MeV $<6 \times 10^{-29}$ 95 47 FILZINGER 2023   Dilaton-like dark matter $<4.5 \times 10^{-12}$ 95 48 HOOF 2023   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $4 \times 10^{-10}$ eV $<3 \times 10^{-12}$ 95 49 HOOF 2023   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = 60 MeV $<2.7 \times 10^{-11}$ 99.7 50 JACOBSEN 2023   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $3 \times 10^{-7}$ eV $<2 \times 10^{-11}$ 99 51 LI 2023 H   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 100$ neV $<3.0 \times 10^{-12}$ 95 52 NOORDHUIS 2023   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $10^{-9} - 10^{-5}$ eV $<5 \times 10^{-11}$ 95 53 PANT 2023   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.1 - 1000$ neV $<5 \times 10^{-26}$ 95 54 SHERRILL 2023   DM Dilaton-like dark matter $<8 \times 10^{-9}$ 95 55 SULAI 2023   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.25 - 2 \times 10^{-14}$ eV $<7.9 \times 10^{-12}$ 56 YAO 2023   ASTR ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ $10^{-13}$ eV $<3.8 \times 10^{-22}$ 95 57 ZHANG 2023 A   Dilaton-like dark matter $<5 \times 10^{-10}$ 90 58 APRILE 2022 B   XENT Solar axions $<1.45 \times 10^{-9}$ 95 59 ARNQUIST 2022   MAJD ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 100 eV $<7 \times 10^{-11}$ 95 60 ARZA 2022   DM ${\mathit m}_{{{\mathit A}^{0}}}=0.2 - 7 \times 10^{-17}$eV $3 - 6 \times 10^{-11}$ 95 61 BERNAL 2022   COSM ${\mathit m}_{{{\mathit A}^{0}}}$ = $8 - 20$ eV $<3.76 \times 10^{-11}$ 95 62 CALORE 2022   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $10^{-11}$ eV $<2 \times 10^{-10}$ 63 CAPUTO 2022   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 500$ MeV $<3 \times 10^{-14}$ 95 64 CASTILLO 2022   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $3 \times 10^{-23}$ eV $<6 \times 10^{-12}$ 90 65 DEROCCO 2022   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $5 - 30$ keV $<5.4 \times 10^{-12}$ 95 66 DESSERT 2022 A   ASTR ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ $3 \times 10^{-7}$ eV $<2.1 \times 10^{-11}$ 95 67 ECKNER 2022   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $2 \times 10^{-7}$ eV $<1 \times 10^{-11}$ 95 68 FOSTER 2022   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $16.5 - 32.5$ $\mu $eV $<1.14 \times 10^{-5}$ 95 69 KIRITA 2022   SAPH ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.5 - 500$ meV $<2 \times 10^{-16}$ 70 LANGHOFF 2022   COSM ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.1 - 3 \times 10^{4}$ keV $<6 \times 10^{-12}$ 95 71 LI 2022   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.2 - 20$ neV $<1.3 \times 10^{-11}$ 95 72 LI 2022 C   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $8 - 200$ neV $<1 \times 10^{-5}$ 73 LUCENTE 2022   ASTR ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ 0.4 MeV $<9.2 \times 10^{-11}$ 95 74 BASU 2021   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $3.6 \times 10^{-21}$ eV $<1.8 \times 10^{-10}$ 95 75 BI 2021   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $2 - 6 \times 10^{-7}$ eV $<1.6 \times 10^{-10}$ 95 76 DOLAN 2021 A   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 570$ keV $<5 \times 10^{-11}$ 95 77 GUO 2021   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $8 - 23$ neV $<1.2 \times 10^{-4}$ 95 78 HOMMA 2021   SAPH ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.4 - 600$ meV $<1.2 \times 10^{-11}$ 95 79 LI 2021 B   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.5 - 500$ neV 80 LLOYD 2021   ASTR Magnetars $<1 \times 10^{-13}$ 95 81 REGIS 2021   DM ${\mathit m}_{{{\mathit A}^{0}}}$ = $2.7 - 5.3$ eV $<1.8 \times 10^{-11}$ 95 82 XIAO 2021   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $3.5 \times 10^{-11}$eV $<7 \times 10^{-4}$ 95 83 ABUDINEN 2020   BEL2 ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.2 - 1$ GeV $<2 \times 10^{-4}$ 90 84 BANERJEE 2020 A   NA64 ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 55 MeV $<1.0 \times 10^{-11}$ 95 85 BUEHLER 2020   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 3 neV $<5 \times 10^{-10}$ 86 CALORE 2020   ASTR ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ $10^{-11}$ eV 87 CARENZA 2020   ASTR Globular clusters $2 - 4 \times 10^{-10}$ 95 88 DENT 2020 A   ASTR Solar axions 89 DEPTA 2020   COSM Axion-like particles $<3.6 \times 10^{-12}$ 95 90 DESSERT 2020 A   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $5 \times 10^{-11}$ eV 91 ESTEBAN 2020   ANIT Axion-like particles $4 - 6 \times 10^{-10}$ 90 92 GAO 2020   ASTR Solar axions $<2.8 \times 10^{-11}$ 95 93 KOROCHKIN 2020   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = 25 eV $\text{none } 6.0 \times 10^{-9} - 1.3 \times 10^{-5}$ 94 LUCENTE 2020 A   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 270 MeV $<2.6 \times 10^{-11}$ 95 95 MEYER 2020   FLAT ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $3 \times 10^{-10}$ eV $<8.4 \times 10^{-8}$ 99 96 YAMAMOTO 2020   COSM ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $4 \times 10^{-6}$ eV $<1 \times 10^{-3}$ 95 97 ALONI 2019   PRMX ${\mathit m}_{{{\mathit A}^{0}}}$ = 0.16 GeV $<1.4 \times 10^{-14}$ 95 98 CAPUTO 2019   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $5 \times 10^{-24}$ eV $<9.6 \times 10^{-14}$ 95 99 FEDDERKE 2019   CMB ${\mathit m}_{{{\mathit A}^{0}}}$ = $10^{-22}$ eV $<7 \times 10^{-13}$ 95 100 IVANOV 2019   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $5 \times 10^{-23}$ eV $<4 \times 10^{-11}$ 95 101 LIANG 2019   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $1.2 \times 10^{-7}$ eV 102 FORTIN 2018   ASTR Axion-like particles $<3 \times 10^{-12}$ 103 JAECKEL 2018   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $30 - 100$ MeV $<5.0 \times 10^{-3}$ 90 104 YAMAJI 2018   LSW ${\mathit m}_{{{\mathit A}^{0}}}$ = $46 - 1020$ eV $<1 \times 10^{-11}$ 99.9 105 ZHANG 2018   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.6 - 4$ neV 106 ADE 2017   CMB Axion-like particles $<6.6 \times 10^{-11}$ 95 107 ANASTASSOPOUL.. 2017   CAST ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 0.02 eV 108 DOLAN 2017   RVUE Axion-like particles $<2.51 \times 10^{-4}$ 95 109 INADA 2017   LSW ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 0.1 eV $>1.5 \times 10^{-11}$ 95 110 KOHRI 2017   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.7 - 50$ neV $<2.6 \times 10^{-12}$ 95 111 MARSH 2017   ASTR ${\mathit m}_{{{\mathit A}^{0}}}{}\leq{}$ $10^{-13}$ eV $<6 \times 10^{-13}$ 112 TIWARI 2017   COSM ${\mathit m}_{{{\mathit A}^{0}}}{}\leq{}$ $10^{-15}$ eV $<5 \times 10^{-12}$ 95 113 AJELLO 2016   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.5 - 5$ neV $<1.2 \times 10^{-7}$ 95 114 DELLA-VALLE 2016   LASR ${\mathit m}_{{{\mathit A}^{0}}}$ = 1.3 meV $<7.2 \times 10^{-8}$ 95 115 DELLA-VALLE 2016   LASR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 0.5 meV $<8 \times 10^{-4}$ 116 JAECKEL 2016   ALPS ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.1 - 100$ GeV $<6 \times 10^{-21}$ 117 LEEFER 2016   ${\mathit m}_{{{\mathit S}^{0}}}$ $<$ $10^{-18}$ eV 118 ANASTASSOPOUL.. 2015   CAST Chameleons $<1.47 \times 10^{-10}$ 95 119 ARIK 2015   CAST ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.39 - 0.42$ eV $<3.5 \times 10^{-8}$ 95 120 BALLOU 2015   LSW ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $2 \times 10^{-4}$ eV 121 BRAX 2015   ASTR ${\mathit m}_{{{\mathit S}^{0}}}$ $<$ $4 \times 10^{-12}$ eV $<5.42 \times 10^{-4}$ 95 122 HASEBE 2015   LASR ${\mathit m}_{{{\mathit A}^{0}}}$ = 0.15 eV 123 MILLEA 2015   COSM Axion-like particles 124 VANTILBURG 2015   Dilaton-like dark matter $<4.1 \times 10^{-10}$ 99.7 125 VINYOLES 2015   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.6 - 185$ eV $<3.3 \times 10^{-10}$ 95 126 ARIK 2014   CAST ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.64 - 1.17$ eV $<6.6 \times 10^{-11}$ 95 127 AYALA 2014   ASTR Globular clusters $<1.4 \times 10^{-7}$ 95 128 DELLA-VALLE 2014   LASR ${\mathit m}_{{{\mathit A}^{0}}}$ = 1 meV 129 EJLLI 2014   COSM ${\mathit m}_{{{\mathit A}^{0}}}$ = $2.66 - 48.8$ $\mu $eV $<8 \times 10^{-8}$ 95 130 PUGNAT 2014   LSW ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 0.3 meV $<1 \times 10^{-11}$ 131 REESMAN 2014   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $1 \times 10^{-10}$ eV $<2.1 \times 10^{-11}$ 95 132 ABRAMOWSKI 2013 A   IACT ${\mathit m}_{{{\mathit A}^{0}}}$ = $15 - 60$ neV $<2.15 \times 10^{-9}$ 95 133 ARMENGAUD 2013   EDEL ${\mathit m}_{{{\mathit A}^{0}}}<$ 200 eV $<4.5 \times 10^{-8}$ 95 134 BETZ 2013   LSW ${\mathit m}_{{{\mathit A}^{0}}}$ = $7.2 \times 10^{-6}$ eV $<8 \times 10^{-11}$ 135 FRIEDLAND 2013   ASTR Red giants $>2 \times 10^{-11}$ 136 MEYER 2013   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $1 \times 10^{-7}$ eV $<8.3 \times 10^{-12}$ 95 137 WOUTERS 2013   ASTR ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $7 \times 10^{-12}$ eV 138 CADAMURO 2012   COSM Axion-like particles $<2.5 \times 10^{-13}$ 95 139 PAYEZ 2012   ASTR ${\mathit m}_{{{\mathit A}^{0}}}<4.2 \times 10^{-14}$ eV $<2.3 \times 10^{-10}$ 95 140 ARIK 2011   CAST ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.39 - 0.64$ eV $<6.5 \times 10^{-8}$ 95 141 EHRET 2010   ALPS ${\mathit m}_{{{\mathit A}^{0}}}<$ 0.7 meV $<2.4 \times 10^{-9}$ 95 142 AHMED 2009 A   CDMS ${\mathit m}_{{{\mathit A}^{0}}}<$ 100 eV $<1.2 - 2.8 \times 10^{-10}$ 95 143 ARIK 2009   CAST ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.02 - 0.39$ eV 144 CHOU 2009   Chameleons $<7 \times 10^{-10}$ 145 GONDOLO 2009   ASTR ${\mathit m}_{{{\mathit A}^{0}}}<$ few keV $<1.3 \times 10^{-6}$ 95 146 AFANASEV 2008   ${\mathit m}_{{{\mathit S}^{0}}}<$ 1 meV $<3.5 \times 10^{-7}$ 99.7 147 CHOU 2008   ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 0.5 meV $<1.1 \times 10^{-6}$ 99.7 148 FOUCHE 2008   ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 1 meV $<5.6 - 13.4 \times 10^{-10}$ 95 149 INOUE 2008   ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.84 - 1.00$ eV $<5 \times 10^{-7}$ 150 ZAVATTINI 2008   ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 1 meV $<8.8 \times 10^{-11}$ 95 151 ANDRIAMONJE 2007   CAST ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 0.02 eV $<1.25 \times 10^{-6}$ 95 152 ROBILLIARD 2007   ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 1 meV $2 - 5 \times 10^{-6}$ 153 ZAVATTINI 2006   ${\mathit m}_{{{\mathit A}^{0}}}$ = $1 - 1.5$ meV $<1.1 \times 10^{-9}$ 95 154 INOUE 2002   ${\mathit m}_{{{\mathit A}^{0}}}$= $0.05 - 0.27$ eV $<2.78 \times 10^{-9}$ 95 155 MORALES 2002 B   ${\mathit m}_{{{\mathit A}^{0}}}<$1 keV $<1.7 \times 10^{-9}$ 90 156 BERNABEI 2001 B   ${\mathit m}_{{{\mathit A}^{0}}}<$100 eV $<1.5 \times 10^{-4}$ 90 157 ASTIER 2000 B   NOMD ${\mathit m}_{{{\mathit A}^{0}}}<$40 eV 158 MASSO 2000   THEO induced ${{\mathit \gamma}}$ coupling $<2.7 \times 10^{-9}$ 95 159 AVIGNONE 1998   SLAX ${\mathit m}_{{{\mathit A}^{0}}}<1$ keV $<6.0 \times 10^{-10}$ 95 160 MORIYAMA 1998   ${\mathit m}_{{{\mathit A}^{0}}}<0.03$ eV $<3.6 \times 10^{-7}$ 95 161 CAMERON 1993   ${\mathit m}_{{{\mathit A}^{0}}}<10^{-3}$ eV, optical rotation $<6.7 \times 10^{-7}$ 95 162 CAMERON 1993   ${\mathit m}_{{{\mathit A}^{0}}}<10^{-3}$ eV, photon regeneration $<3.6 \times 10^{-9}$ 99.7 163 LAZARUS 1992   ${\mathit m}_{{{\mathit A}^{0}}}<0.03$ eV $<7.7 \times 10^{-9}$ 99.7 163 LAZARUS 1992   ${\mathit m}_{{{\mathit A}^{0}}}$= eV $<7.7 \times 10^{-7}$ 99 164 RUOSO 1992   ${\mathit m}_{{{\mathit A}^{0}}}<10^{-3}$ eV $<2.5 \times 10^{-6}$ 165 SEMERTZIDIS 1990   ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $7 \times 10^{-4}$ eV 1  ABRAHAM 2025 search for axions as a long-lived particle decaying into photons in the FASER detector at the LHC. They constrain models where the axion dominantly couples to ${{\mathit W}}$ bosons. The quoted limit is from their Fig. 11, which shows the bound interpreted in terms of a coupling to photons, taking the value at a mass of 70 MeV where the constraint is strongest. Bounds on the axion-gluon coupling extend up to axion masses of up to 800 MeV. 2  ADAMS 2025C present a search for ALP-photon mixing imprinted on the gamma-ray spectrum of the flaring NGC 1275 radio galaxy at the centre of the Perseus cluster observed by the VERITAS observatory. They adopt the CLs method for reporting exclusion limits as shown in their Fig. 3. No point in the tested parameter space is excluded at or above 95$\%$ confidence. The quoted limit is reached at ${\mathit m}_{{{\mathit A}^{0}}}$ = $3.03 \times 10^{-7}$ eV. 3  ALTENMULLER 2025 primarily reports a new limit from the CAST helioscope on the product of the axion-photon and axion-electron coupling, but they also exploit the same analysis to set a new limit on the axion-photon coupling alone, although this is weaker than their previous limit in ALTENMULLER 2024. 4  CANDON 2025 place bounds on heavy photon-coupled axion-like particles produced in the interiors of the stars in the starburst galaxy M82 and then decaying to two photons. This process would generate an X-ray flux peaking around 100 keV, which they search for using data from the NuSTAR space telescope. See their Fig. 2 for mass-dependent limits. 5  CHEN 2025 use data from X-ray satellites Chandra and eROSITA to search for the decays of axion-like particles produced by the Alpha Centauri binary system. Specifically, they consider the argument also used by BEAUFORT 2023 in the case of the Sun, in which axions emitted with low speed from the star can build up in a gravitationally trapped 'basin' over the star's life. See their Fig. 3 for mass-dependent limits. The quoted value applies to the case where the axion-electron coupling is taken to be negligible. 6  CHEN 2025A constrain low-mass axion-like particles by searching for the imprints of axion-photon oscillations on the gamma-ray spectra of two active galactic nuclei measured by the Fermi and MAGIC gamma-ray telescopes. See their Fig. 11 for mass-dependent limits. 7  CHEN 2025B constrain low-mass axion-like particles by searching for the imprints of axion-photon oscillations on the gamma-ray spectra of several blazars observed by the Fermi gamma-ray telescope. See Figs. 2, 3 and 4 for mass-dependent limits. 8  FONG 2025 use early-release data from the eROSITA X-ray telescope's Final Equatorial Depth Survey to search for axion-like particle dark matter decaying to two photons in the Milky Way's dark matter halo. See their Fig. 7 for mass-dependent limits. 9  GOLDSTEIN 2025 place bounds on low mass axions mixing with photons over cosmological distances as they traverse large-scale structure, which would lead to an observable patchy screening effect in CMB anisotropy maps. See their Fig. 3 for mass-dependent limits. This bound is analogous to that placed on dark photons by MCCARTHY 2024. 10  HAYRAPETYAN 2025Z places a bound on heavy axion-like particles coupled to photons via measurements of light-by-light scattering in ultraperipheral PbPb collisions at the CMS experiment. The bound is based on a search for diphoton events due to ${{\mathit \gamma}}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit a}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ on top of the light-by-light scattering continuum. See Fig. 9 for mass-dependent limits on the axion-photon coupling. 11  JANISH 2025 use blank-sky observations of the James Webb Space Telescope to search for dark matter axions present in the galactic halo. eV-mass axions decaying into two photons would present an emission line in the infrared band. See their Fig. 2 for mass-dependent limits. 12  KAR 2025 use infrared to ultraviolet observations of the giant elliptical galaxy M87 to search for evidence of eV-scale axions decaying to two photons, assuming they make up the dark matter halo of the galaxy. See their Fig. 2, 3 and 4 for mass-dependent limits. 13  KIRITA 2025 presents a new result from the SAPPHIRES collaboration, namely a search for the production of axion-like particles in a quasi-parallel stimulated resonant photon-photon collider. See their Fig. 11 for mass-dependent limits. 14  LI 2025D search for evidence of axion-photon mixing imprinted on the gamma-ray spectrum of the flat-spectrum radio quasar Ton-599 detected by Fermi-LAT. See their Fig. 4 for mass-dependent limits. 15  MIRZAKHANI 2025 search for axion-like particles coupled to photons using the MINER reactor neutrino experiment. Their search assumes axions would be produced via Primakoff emission from the reactor photon flux, which can then decay to two photons or convert to a photon through the inverse Primakoff effect in the detector. See Fig. 10 for mass-dependent limits. 16  NING 2025 sets bounds on low-mass axion-like particle Primakoff emission by stars in the M87 and M82 starburst galaxies. They use data from the NuSTAR space telescope to search for evidence of the emitted axions converting into hard X-ray photons in the surrounding galactic magnetic fields. See Fig. 2 for mass-dependent limits. 17  PARK 2025 present a search for axion-like particles from the NEON reactor neutrino experiment. Axions would be produced by the large MeV photon flux from the reactor and subsequently scatter or decay to a photon pair in the detector. The quoted limit is at ${\mathit m}_{{{\mathit A}^{0}}}$ = 3 MeV. See their Fig. 3 for mass-dependent limits. 18  RUZ 2025 use data from the NuSTAR X-ray telescope to search for solar axions converting into photons as they traverse the Sun's atmospheric magnetic field. For larger ${\mathit m}_{{{\mathit A}^{0}}}$, the limit becomes weaker due to loss of coherence in the conversion. See their Fig. 1 for mass-dependent limits. 19  TODARELLO 2025 use observations of dwarf spheroidal galaxies and galaxy clusters made by the Hubble Space Telescope to constrain axions decaying to two photons at UV wavelengths, assuming axions make up the dark matter halos of those astrophysical objects. See their Fig. 3 for mass-dependent limits. 20  TROITSKY 2025 searches for evidence of any anomalous cooling due to axion emission from red giants and helium-burning stars in seven globular clusters observed by the Gaia survey. A 3.3$\sigma $ hint for anomalous cooling is found, which could be explained by a non-zero axion-photon coupling. 21  YIN 2025 use the WINERED spectrograph on the Magellan Clay Telescope to search for evidence of dark matter axions decaying into photons in the halos of the Leo V and Tucana II dwarf spheroidal galaxies. See their Fig. 1 for mass-dependent limits and the dependence on the assumed dark matter halo models. 22  ZENG 2025 place a bound on axions emitted by the Sun due to a nonzero axion-photon coupling using electronic recoil data collected by the PandaX detector. Electron recoil events are generated via the axion-photon coupling by the inverse Primakoff effect. The limit is independent of the axion mass up to around the core temperature of the Sun. 23  ABLIKIM 2024AD constrain the axion-photon coupling through radiative ${{\mathit J / \psi}}$ decays in the BESIII detector at the Beijing electron-positron collider. See their Fig. 5 for mass-dependent limits. 24  ALTENMULLER 2024 report an extended search for solar axions using the CAST experiment. The experiment employed a new xenon-based microMEGAS detector - a pathfinder for the future International Axion Observatory (IAXO). This limit improves upon ANASTASSOPOULOS 2017. See Fig. 4 for mass-dependent limits. 25  DEV 2024 use Fermi gamma-ray observations of the neutron star merger GW170817 to constrain the production and subsequent decay of high-mass axion-like particles. Constraint extends diagonally in mass-coupling space, reaching $7 \times 10^{-12}$ GeV${}^{-1}$ at 100 MeV. See Fig. 4 for mass-dependent limits. 26  DIAMOND 2024 use multi-messenger observations of the neutron star merger GW170817 to constrain the production and radiative decay of axions in the event. Limits shown in their Fig. 3 extend diagonally in mass-coupling space. 27  FORDHAM 2024 use asteroseismology observations of a solar-like star, KIC 6933899, to constrain axion emission from its interior via the photon coupling. Bound applies to all axion masses up to around the core temperature of the star $\sim{}$keV. 28  GAO 2024 constrain ALP-photon oscillations via their imprint on the gamma-ray spectrum of the blazar Mrk 421, as observed by MAGIC and Fermi-LAT. See their Fig. 5 for mass-dependent limits. 29  GAO 2024A constrain ALP-photon oscillations using the high-energy gamma-ray spectrum observed by LHAASO of the brightest gamma-ray burst so far detected, GRB 221009A. See their Fig. 5 for mass-dependent limits. The strength of the limit depends on the magnetic field of the host galaxy. 30  GUO 2024 search for axion dark matter decaying or converting into photons in the Coma Berenices dwarf galaxy using the radio telescope FAST. The quoted limit is for the case of axions decaying, including stimulated emission. See their Fig. 2 for mass-dependent limits. 31  LI 2024A constrain the imprint of ALP-photon oscillations on the TeV gamma-ray spectrum of the BL Lac blazar 1ES 1215+303 using VERITAS and Fermi-LAT data. See their Fig. 4 for mass-dependent limits. 32  LI 2024B constrain the imprint of ALP-photon oscillations on the very-high-energy gamma-ray spectrum of various galactic sources detected by the LHAASO air-shower array. Best limits are obtained from the Crab Nebula after combining several observations from different gamma-ray observatories in addition to LHAASO. See their Fig. 5 for mass-dependent limits. 33  LI 2024D search for evidence of axion-photon oscillations imprinted on the gamma-ray spectrum of the nearby BL Lac blazar Markarian 421. They set upper limits using data from Fermi-LAT and HAWC. The quoted limit applies for ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ $3 \times 10^{-9}$ eV. See their Fig. 3 for mass-dependent limits. 34  MANZARI 2024 search for evidence of axions produced in SN1987A converting into gamma-rays that would have been detectable by the Solar Maximum Mission. This analysis improves upon previous studies of axion-photon conversion after SN1987A (e.g. HOOF 2023) by including the magnetic field of the progenitor star. Quoted limit applies for masses below 0.1 neV and rises towards larger masses. See their Fig. 1 for mass-dependent limits. 35  PANT 2024 searches for the imprint of axion-photon oscillations in the very-high-energy gamma-ray spectrum of the quasar QSO B1420+326 observed by the MAGIC telescope. Three small disconnected regions of mass-coupling parameter space below 1 neV are ruled out. See Fig. 4 for the limits. 36  PYBUS 2024 report results from the GlueX detector, which has searched for the two-photon decay of heavy axions produced through the nuclear Primakoff effect due to a beam of photons incident on a Carbon target. See their Fig. 8 for mass-dependent limits. 37  RAVENSBURG 2024 search for heavy axions decaying to two photons using the recent nearby type-II supernova SN 2023ixf. Constraint extends diagonally downwards in mass-coupling space, see their Fig. 2 for full limits. Quoted limit is the most constraining point for the most conservative choices for supernova parameters. 38  TODARELLO 2024 search for axions decaying to two photons in the halos of Milky Way dwarf galaxies observed in the MUSE-Faint survey. This study improves upon an earlier one presented in REGIS 2021. See their Fig. 5 for compiled mass-dependent limits. 39  WANG 2024A search for axions decaying into two photons assuming that they make up the dark matter halos of galaxies. They use data from the Dark Energy Spectroscopic Instrument, searching for the axion decay line in optical wavelengths with their Bright Galaxy and Luminous Red Galaxy samples. See their Fig. 8 for mass-dependent limits on the axion to photon decay rate. Their constraint is quoted as a 5$\sigma $ detection limit. 40  BATTYE 2023 look for dark-matter axions falling into pulsar magnetospheres and converting into narrow radio lines. Unlike the earlier FOSTER 2022 they search for evidence of conversion in the time-domain signal of a single pulsar, using 1 hour of MeerKAT data on the pulsar PSR J2144-3933. The quoted limit applies to an assumed magnetic field of $2 \times 10^{12}$ G and a dark matter density of 0.45 GeV/cm${}^{3}$. 41  BEAUFORT 2023 extends DEROCCO 2022 who searched for the X-ray decay of axions that build up in the gravitational well of the Sun over its lifetime, the 'solar basin'. They use data from NuSTAR and SphinX telescopes and extends the previous study by accounting for the axion production via photon coalescence. 42  BERNAL 2023 use gamma-ray data from 739 blazars observed by FermiLAT and 38 blazars by Cherenkov observatories. They estimate optical depth, subtract the astrophysical component, and attribute the residual to axion two-photon decay. The quoted limit is for ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ 25 eV. See their Fig. 3 for the mass-dependent limits. 43  CAPOZZI 2023 use Planck CMB and Lyman-$\alpha $ observations to set limits on early energy injection by decaying dark matter axions that would affect CMB anisotropies and the reionisation history of the Universe. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = 100 eV and the reionization model of Fauchere-Giguere. See Fig. 4 for mass-dependent constraints from different reionization models. 44  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 100 MeV but the limit does not extend to arbitrarily large couplings. See Fig. 7 for mass-dependent limits. 45  DAVIES 2023 is analogous to AJELLO 2016, and use the Fermi-LAT data from three quasars (3C454.3, CTA 102, and 3C279), considering the blazer jets as the regions where the axion-photon oscillations occur. See Fig. 8 for the mass-dependent limits. 46  DIAMOND 2023 demonstrate that a window of decaying 10-MeV-mass ALP parameter space previously thought to be excluded by the lack of gamma-ray emission from the SN 1987A explosion is actually unconstrained because of the formation of a fireball that would prevent decay photons from escaping. They nevertheless re-exclude this window by considering the non-detection of the sub-MeV emission by the Pioneer Venus Orbiter. The quoted limit is at ${\mathit m}_{{{\mathit A}^{0}}}$ = 56 MeV. See their Fig. 2 for mass-dependent limits. 47  FILZINGER 2023 searched for oscillations in the fine structure constant induced by dilaton-like dark matter by measuring the frequency ratio between the E3 and E2 transitions of ${}^{171}\mathrm {Yb}{}^{+}$. They assume the local dark matter density ${{\mathit \rho}_{{{S}}}}$ = 0.4 GeV/cm${}^{3}$. The quoted limit is set at ${\mathit m}_{{{\mathit S}^{0}}}$ $\simeq{}$ $4 \times 10^{-23}$ eV. See their Fig. 4 for the limits over ${\mathit m}_{{{\mathit S}^{0}}}$ = $1 \times 10^{-24} - 1 \times 10^{-17}$ eV. 48  HOOF 2023 consider axions emitted from SN1987A converting to gamma rays in Galactic magnetic fields, using temporal information of the Solar Maximum Mission data. They set a limit $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}{ {}\lesssim{} }$ $5 \times 10^{-12}$ for masses ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ $2 \times 10^{-10}$ eV. See left panel in Fig. 3 for mass-dependent limits. 49  HOOF 2023 look for gamma rays resulting from the decay of axions produced from SN1987A, using the Solar Maximum Mission data. See right panel in Fig. 3 for mass-dependent limits. 50  JACOBSEN 2023 search for the imprints of axion-photon mixing on the TeV spectra of several blazars using data from the HAWC air shower detector. 51  LI 2023H look for gamma-ray spectral irregularities induced by axion-photon oscillations from AGN VER J0521+211, using the Fermi-LAT and VERITAS data. See their Fig. 4 for mass-dependent limits. 52  NOORDHUIS 2023 places strong constraints on the axion-photon coupling over a broad mass window using the fact that the polar cap regions of pulsars can generate a population of axions, which would then convert into an observable outgoing radio flux in the presence of the neutron star's B-field. They search for this signal in 27 pulsars and set mass-dependent limits shown in their Fig. 2. 53  PANT 2023 study the effect of axion-photon oscillations on the gamma-ray spectrum from the extragalactic neutrino source, TXS 0506+056. The quoted limit is at ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ $2.7 \times 10^{-7}$ eV. See their Fig. 2 for mass-dependent limits. 54  SHERRILL 2023 search for scalar dilaton-like dark matter via oscillations in the fundamental constants. Their most competitive constraint is on the scalar photon coupling (Fig. 6, upper panel) that affects the fine-structure constant, which they extract using an optical-to-optical clock comparison between ${}^{171}\mathrm {Yb}{}^{+}$ and ${}^{87}\mathrm {Sr}$. Quoted limit applies at the smallest mass in their search window for this case of $10^{-20}$ eV. 55  SULAI 2023 looked for ultralight axion dark matter using the ``Earth as a transducer" concept over the 0.5 to 5 Hz frequency range. They situate several magnetometers at magnetically quiet places and search for spatially-correlated magnetic field patterns induced by axion dark matter interacting in the effective cavity formed between the Earth's surface and the ionosphere. See their Fig. 12 for mass-dependent limits in context. This limit extends to higher-frequencies than their previous limit using archival geomagnetic field data collected by the SuperMAG collaboration, see ARZA 2022 56  YAO 2023 study an optical circular polarization in blazers induced by the axion-photon mixing. The quoted limit assumes the transverse magnetic field at the jet's emission site, with $\mathit B_{T}$ = 1 G, and this limit inversely scales with $\mathit B_{T}$. See their Fig. 3 for the limits' dependence on $\mathit B_{T}$ and electron density. 57  ZHANG 2023A searched for oscillations in the fine structure constant induced by dilaton-like dark matter by measuring the frequencies of a hyperfine-structure transition in ${}^{87}\mathrm {Rb}$ and an electronic transition in ${}^{164}\mathrm {Dy}$, and by comparing them with that of a quartz oscillator. They assume the local dark matter density ${{\mathit \rho}_{{{S}}}}$ $\simeq{}$ 0.4 GeV/cm${}^{3}$. The quoted limit is set at ${\mathit m}_{{{\mathit S}^{0}}}$ $\simeq{}$ $1 \times 10^{-17}$ eV. See their Fig. 3 for the limits over ${\mathit m}_{{{\mathit S}^{0}}}$ = $1 \times 10^{-17} - 8.3 \times 10^{-13}$ eV. 58  APRILE 2022B is an update of APRILE 2020 based on a similar solar axion modeling to DENT 2020A and GAO 2020. They exclude the XENON1T excess found in APRILE 2020. The quoted limit holds for small $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$. See Fig. 6 for correlation between $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ and $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$. 59  ARNQUIST 2022 is analogous to AVIGNONE 1998, and supersedes ANASTASSOPOULOS 2017 for ${\mathit m}_{{{\mathit A}^{0}}}{ {}\gtrsim{} }$ 1.2 eV. 60  ARZA 2022 search for low-mass axions as dark matter using the Earth as a transducer for axion-photon conversion. The concept works because the region between the Earth and the ionosphere forms an insulating cavity that parametrically enhances the axion signal by the radius of the Earth. The result is an oscillating and spatially correlated magnetic field induced via the interaction between axion dark matter and the geomagnetic field, which they searched for using archival magnetometer field data over 20 years compiled by the SuperMAG collaboration. Quoted limit applies for masses $3 - 4 \times 10^{-17}$ eV, see Fig. 1 for mass-dependent limits. 61  BERNAL 2022 explored the possibility that the excess in the cosmic optical background measured by New Horizonss Long Range Reconnaisance Imager was due to axion dark matter decaying into monoenergetic photons. See their Fig. 2 for the axion-photon coupling to explain the excess. 62  CALORE 2022 update CALORE 2020 by evaluating axion fluxes from progenitors of various masses and performing a template-based analysis using 12 years of Fermi-LAT data in the energy range from 50 MeV to 500 GeV. See their Fig. 10 for mass-dependent limits. 63  CAPUTO 2022 study the effect of energy deposition by radiative decay of axions produced via the Primakoff process and photon coalescence in the supernova core, and set the limits by the radiative energy deposition $<$ $10^{50}$ erg and progenitor radius = $5 \times 10^{13}$ cm. The quoted limit is at ${\mathit m}_{{{\mathit A}^{0}}}$ = 150 MeV. See their Fig. 2 for mass-dependent limits. 64  CASTILLO 2022 update CAPUTO 2019 using the polarization measurements of the Crab Pulsar by the QUIJOTE MFI instrument and 20 Galactic pulsars from the PPTA project. See their Table 1 for the assumed local axion energy density ${{\mathit \rho}_{{{A}}}}$ for each pulsar and their Fig. 7 for the mass-dependent limits in the range of $3 \times 10^{-23}$ eV ${}\leq{}{\mathit m}_{{{\mathit A}^{0}}}{}\leq{}$ $10^{-19}$ eV. 65  DEROCCO 2022 uses the NuSTAR data to search for monochromatic X-ray lines produced by the decay of solar axions trapped on bound orbits. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ 9 keV. They also derive limits in the plane of $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$ and $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$. See their Figs. 2 and 4 for mass-dependent limits. 66  DESSERT 2022A look for an axion-induced linear polarization using data from multiple magnetic white dwarf stars. See their Figs. 1 and 8 for the mass-dependent limits. 67  ECKNER 2022 set limits by using sub-PeV diffuse gamma-ray data from HAWC and Tibet AS${{\mathit \gamma}}$ by assuming that gamma rays produced simultaneously with high-energy neutrinos from extragalactic sources suggested by IceCube are converted to axions in the magnetic field at the source and reconverted to gamma rays in the Galactic magnetic field. See their Fig. 4 for mass-dependent limits. 68  FOSTER 2022 is an update of FOSTER 2020 in the list of limits on relic invisible axions. They search for axion-photon transitions generated by neutron stars in the Galactic center region. They use improved population models of the Galactic center neutron stars and a Navarro-Frenk-White (NFW) model of the galactic dark matter distribution. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ $17 - 25$ $\mu $eV. See their Fig. 1 for mass-dependent limits. 69  KIRITA 2022 update HOMMA 2021 by increasing the laser energy and developing a background discrimination method using the beam cross-section dependence of the background originated from optical elements. The quoted limits applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = 0.18 eV. See their Fig. 11 for mass-dependent limits. 70  LANGHOFF 2022 set limits by considering the freeze-in production of axions coupled only to photons. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ = 2 MeV for the reheating temperature equal to 5 MeV. See their Fig. 1 for mass-dependent limits. 71  LI 2022 is analogous to LI 2021B, and use the spectra of the blazar FSRQ 4C+21.35 measured by MAGIC, VERITAS, and Fermi-LAT. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ $8 \times 10^{-10}$ eV. See their Fig. 1 for mass-dependent limits. 72  LI 2022C is analogous to LI 2021B, and use the spectra of the blazars Mrk 421 and PG 1553+113 measured by MAGIC and Fermi-LAT. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ $1 \times 10^{-8}$ eV. See their Fig. 4 for mass-dependent limits. 73  LUCENTE 2022 developed a method to correctly incorporate the effects of axions decaying into photons inside the core of horizontal-branch stars. They update CARENZA 2020 by evaluating axion energy transfer in the range of axion mean free path where the diffusive energy transport and free streaming approximations are not applicable. See their Fig. 1 for the limits. 74  BASU 2021 searched for birefringence induced by axion dark matter using multiple images of the polarized source in the strongly gravitationally lensed system CLASS B1152+199. They assume the axion makes up all dark matter, and used the axion density in the emitting region, ${{\mathit \rho}_{{{A}}}}$ = 20 GeV/cm${}^{3}$. Limits between $9.2 \times 10^{-11} - 7.7 \times 10^{-8}$ GeV${}^{-1}$ are obtained for ${\mathit m}_{{{\mathit A}^{0}}}$ = $3.6 \times 10^{-21} - 4.6 \times 10^{-18}$eV. See their Fig. 2 for mass-dependent limits. 75  BI 2021 look for the gamma-ray spectral distortions induced by axion-photon oscillations in the presence of the Galactic magnetic field, using the measurements of sub-PeV gamma-rays from the Crab Nebula by the Tibet AS${{\mathit \gamma}}$ and HAWC experiments, together with MAGIC and HEGRA gamma-ray data. See their Fig. 3 for mass-dependent limits. 76  DOLAN 2021A study the effect of axion production on the evolution of asymptotic giant branch stars, and use the white-dwarf initial-final mass relation to set the limits. See their Fig. 1 for mass-dependent limits. 77  GUO 2021 is analogous to AJELLO 2016, and use the Fermi-LAT and H.E.S.S. II measurements of PG 1553+113 and PKS 2155-304. See their Fig. 6 for mass-dependent limits. 78  HOMMA 2021 look for the production of axion resonance states and their subsequent stimulated decays by combining linearly polarized creation laser pulses and circularly polarized inducing laser pulses. The quoted limit is at ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ 0.178 eV. See their Fig. 14 for mass-dependent limits. 79  LI 2021B is analogous to AJELLO 2016, and use the spectra of the blazar Mrk 421 measured by ARGO-YBJ and Fermi-LAT. They consider ALP-photon mixing in the magnetic fields of both the blazar jet and the Galaxy. The quoted limit applies to ${\mathit m}_{{{\mathit A}^{0}}}$ $\simeq{}$ $1 \times 10^{-9}$ eV. See their Fig. 5 for mass-dependent limits. 80  LLOYD 2021 is analogous to FORTIN 2018, and set limits on the product of the axion couplings to photons and nucleons as $\mathit g_{{{\mathit A}} {{\mathit N}} {{\mathit N}}}$ $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}{ {}\lesssim{} }$ $4.6 \times 10^{-19}$ GeV${}^{-1}$ for ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ $10^{-5}$ eV by using the quiescent soft gamma-ray flux upper limits in five magnetars. We use $\mathit g_{{{\mathit A}} {{\mathit N}} {{\mathit N}}}$ = $\mathit G_{{{\mathit A}} {{\mathit N}}}$ 2${\mathit m}_{{{\mathit N}}}$ to translate their limits. See their Table II and Fig. 3 for the limits. 81  REGIS 2021 look for monochromatic photons from axion decay, using the MUSE spectroscopic data on the Leo T dwarf spheroidal galaxy. They assume that axions make up all of dark matter and use the integrated dark matter density along the line of sight determined by observations. 82  XIAO 2021 use X-ray data from Betelgeuse to look for signals from axions produced in the stellar core that were converted to X-rays by the Galactic magnetic field. See their Fig. 1 for the mass-dependent limit. 83  ABUDINEN 2020 look for the process ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit A}^{0}}$ (${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$) and set upper limits of around $10^{-3}$ over the mass range. The quoted limit is at ${\mathit m}_{{{\mathit A}^{0}}}$ = 0.3 GeV. See their Fig. 5 for mass dependent limits. 84  BANERJEE 2020A look for axions produced from high-energy bremsstrahlung photons through the Primakoff effect with the electric field of the target nuclei. They exclude $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$= $2 \times 10^{-4} - 5 \times 10^{-2}$ GeV${}^{-1}$ for ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 55 MeV. See their Fig. 5 for mass-dependent limits. 85  BUEHLER 2020 look for the ${{\mathit \gamma}}$-ray transparency due to axion-photon oscillations using high-energy photon events from 79 sources in the Second Fermi-LAT Catalog of High-Energy Sources. The quoted limit is for the intergalactic magnetic field strength and coherence length of $\mathit B$ = 1 nG and $\mathit s$ = 1 Mpc. See their Figs. 4 and 5 for mass-dependent limits and for different magnetic-field parameters. 86  CALORE 2020 use the isotropic diffuse ${{\mathit \gamma}}$-ray background measured by the Fermi-LAT to constrain the ${{\mathit \gamma}}$-ray flux converted in the Galactic magnetic field from axions produced from past core-collapse supernovae. They also derive a limit on a heavier axion with ${\mathit m}_{{{\mathit A}^{0}}}{ {}\gtrsim{} }$ keV decaying into two photons of $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}{ {}\lesssim{} }$ $5 \times 10^{-11}$ GeV${}^{-1}$ for ${\mathit m}_{{{\mathit A}^{0}}}$ = 5 keV. See their Figs. 5 and 7 for the limits as well as limits in the presence of axion-nucleon couplings. 87  CARENZA 2020 extend the globular cluster bound of AYALA 2014 to heavier masses (${\mathit m}_{{{\mathit A}^{0}}}{}\leq{}$ a few 100 keV) by taking account of the coalescence process ${{\mathit \gamma}}$ ${+}$ ${{\mathit \gamma}}$ $\rightarrow$ ${{\mathit A}^{0}}$ as well as the decay of the ALP inside the stellar core. See their Fig.4 for mass-dependent limits. 88  DENT 2020A is analogous to GAO 2020. The quoted limit is from their arXiv:2006.15118v3 (v2 is their published version), using the relativistic Hartree-Fock form factor. The limit is up to two times weaker than the published one. See Fig. 4 in their arXiv version 3 for the correlation between $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ and $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$ corresponding to the excess reported in APRILE 2020. 89  DEPTA 2020 correct the underestimated ${}^{}\mathrm {D}$ abundance in MILLEA 2015, and derive robust cosmological bounds by allowing the reheating temperature, $\mathit N_{{\mathrm {eff}}}$, and neutrino chemical potential to vary. See their Fig. 6 for mass-dependent limits. 90  DESSERT 2020A use the NuSTAR data of the Quintuplet and Westerlund 1 super star clusters to look for X-rays converted in the Galactic magnetic field from the axions produced in stellar cores. See their Fig. 3 for the mass-dependent limits. 91  ESTEBAN 2020 show that the two anomalous ANITA events can be explained by the reflected radio pulses that are resonantly produced in the ionosphere via axion-photon conversion for ${\mathit m}_{{{\mathit A}^{0}}}{ {}\lesssim{} }$ $1 \times 10^{-7}$ eV , if an axion clump passes the Earth about once a month. See their Fig.5 for the region consistent with this interpretation for different values of the axion density inside the clumps. 92  GAO 2020 correct the limit of APRILE 2020 by including inverse Primakoff scattering in the XENON1T detector. The quoted limit is from their arXiv:2006.14598v4 (v3 is their published version), taking account of the atomic form factor of ${}^{}\mathrm {Xe}$ as pointed out in ABE 2020J. The limit is weaker by a factor of $1.5 - 2$ than the published one. See Fig. 3 in their arXiv version 4 for correlation between $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ and $\mathit g_{{{\mathit A}} {{\mathit e}} {{\mathit e}}}$ corresponding to the excess reported in APRILE 2020. 93  KOROCHKIN 2020 assume the axion makes up all dark matter, and look for a dip in the observed gamma-ray spectrum of the blazer 1ES 1218+304 by Fermi/LAT and VERITAS due to the extragalactic background light produced by the axion decay. Their analysis favors nonzero axion-induced absorption with $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ = $3 \times 10^{-11} - 2 \times 10^{-10}$ GeV${}^{-1}$ over a range of ${\mathit m}_{{{\mathit A}^{0}}}$ = $2 - 18$ eV. See their Fig. 1 for mass-dependent limits between 0.25 $<$ ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 25 eV. 94  LUCENTE 2020A study the SN 1987A energy-loss argument on the axion-like particle production. In addition to the Primakoff process, they take account of photon coalescence as well as gravitational trapping that become relevant at ${\mathit m}_{{{\mathit A}^{0}}}$ $>$ 100 MeV. See their Fig. 12 for the mass-dependent limit. 95  MEYER 2020 look for prompt $\gamma $-rays converted in the Galactic magnetic fields from axions produced via the Primakoff process in a sample of 20 extragalactic core-collapse supernovae. The limits assume a progenitor mass of 10 times the solar mass and certain models for the optical emission and the galactic magnetic field. See their Figs. 2 and 6 in the erratum for mass- and model-dependent limits. 96  YAMAMOTO 2020 look for X-ray photons converted by the Earth's magnetic field from the axions produced by the two-body decay of dark matter, and set the limits by using the Suzaku data. The quoted limit is for the monochromatic X-ray line from the galactic dark matter with lifetime $\tau $ = $4.32 \times 10^{17}$ sec. They also derive limits on the continuum spectrum from the extragalactic component. See their Fig. 7 for the limits. 97  ALONI 2019 used the data collected by the PRIMEX experiment to derive a limit based on a data-driven method. See their Fig. 2 for mass-dependent limits. 98  CAPUTO 2019 look for an oscillating variation of the polarization angle of the pulsar J0437-4715, where they assume the local axion energy density ${{\mathit \rho}_{{{A}}}}$ = 0.3 GeV/cm${}^{3}$. See their Fig. 2 for mass-dependent limits for $5 \times 10^{-24}$ eV ${}\leq{}{\mathit m}_{{{\mathit A}^{0}}}{}\leq{}$ $2 \times 10^{-19}$ eV. 99  FEDDERKE 2019 look for a uniform reduction of the CMB polarization at large scales, which is induced by the oscillating axion background during CMB decoupling. The quoted limit is based on the assumption that axions make up all of the dark matter. See their Fig. 3 for mass-dependent limits for ${\mathit m}_{{{\mathit A}^{0}}}$ = $10^{-22} - 10^{-19}$ eV. 100  IVANOV 2019 look for the axion-induced periodic changes in the polarization angle of parsec-scale jets in active galactic nuclei observed by the MOJAVE program, where they use the axion energy density ${{\mathit \rho}_{{{A}}}}$ = 20 GeV/cm${}^{3}$. See their Fig. 6 for mass-dependent limits for $5 \times 10^{-23}$ eV ${}\leq{}{\mathit m}_{{{\mathit A}^{0}}}{}\leq{}$ $1.2 \times 10^{-21}$ eV. 101  LIANG 2019 look for spectral irregularities in the spectrum of 10 bright H.E.S.S. sources in the Galactic plane, assuming photon-ALP mixing in the Galactic magnetic fields. See their Fig. 2 for mass-dependent limits with different Galactic magnetic field models. 102  FORTIN 2018 studied the conversion of axion-like particles produced in the core of a magnetar to hard X-rays in the magnetosphere. See their Fig. 5 for mass-dependent limits with different values of the magnetar core temperature. 103  JAECKEL 2018 study axions produced through the Primakoff process from SN 1987A, which subsequently decay into photon pairs. See their Fig. 1 for the mass-dependent limits in the range of ${\mathit m}_{{{\mathit A}^{0}}}$ = $0.01 - 100$ MeV. 104  YAMAJI 2018 search for axions with an x-ray LSW at Spring-8, using the Laue-case conversion in a silicon crystal. They also obtain $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ $<$ $4.2 \times 10^{-3}$ GeV${}^{-1}$ for ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ 10 eV. See their Fig. 5 for mass-dependent limits. 105  ZHANG 2018 look for spectral irregularities in the spectrum of PKS 2155-304 measured by Fermi LAT, assuming photon-ALP mixing in the intercluster and Galactic magnetic fields. See their Figs. 2 and 3 for mass-dependent limits with different values of the intercluster magnetic field parameters. 106  ADE 2017 look for cosmic birefringence from axion-like particles using CMB polarization data taken by the BICEP2 and Keck Array experiments. They set a limit $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}\mathit H_{I}$ $<$ $7.2 \times 10^{-2}$ at 95 $\%$CL for ${\mathit m}_{{{\mathit A}^{0}}}$ $<$ $10^{-28}$ eV, where $\mathit H_{I}$ is the Hubble parameter during inflation. 107  ANASTASSOPOULOS 2017 looked for solar axions by the CAST axion helioscope in the vacuum phase, and supersedes ANDRIAMONJE 2007. 108  DOLAN 2017 update existing limits on $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ for axion-like particles. The limits from the proton beam dump experiments in their Fig. 2 contained an error, and the corrected version is shown in Fig. 1 of DOLAN 2021. 109  INADA 2017 search for axions with an x-ray LSW at Spring-8. See their Fig. 4 for mass-dependent limits. 110  KOHRI 2017 attributed to axion-photon oscillations the excess of cosmic infrared background observed by the CIBER experiment. See their Fig. 5 for the region preferred by their scenario. 111  MARSH 2017 is similar to WOUTERS 2013, using Chandra observations of M87. See their Fig. 6 for mass-dependent limits. 112  TIWARI 2017 use observed limits of the cosmic distance-duality relation to constrain the photon-ALP mixing based on 3D simulations of the magnetic field configuration. The quoted value is for the averaged magnetic field of 1nG with a coherent length of 1 Mpc. See their Fig. 5 for mass-dependent limits. 113  AJELLO 2016 look for irregularities in the energy spectrum of the NGC1275 measured by Fermi LAT, assuming photon-ALP mixing in the intra-cluster and Galactic magnetic fields. See their Fig. 2 for mass-dependent limits. 114  DELLA-VALLE 2016 look for the birefringence induced by axion-like particles. See their Fig. 14 for mass-dependent limits. 115  DELLA-VALLE 2016 look for the dichroism induced by axion-like particles. See their Fig. 14 for mass-dependent limits. 116  JAECKEL 2016 use the LEP data of ${{\mathit Z}}$ $\rightarrow$ 2 ${{\mathit \gamma}}$ and ${{\mathit Z}}$ $\rightarrow$ 3 ${{\mathit \gamma}}$ to constrain the ALP production via ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$ $\rightarrow$ ${{\mathit A}^{0}}$ ${{\mathit \gamma}}$ (${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$), assuming the ALP coupling with two hypercharge bosons. See their Fig. 4 for mass-dependent limits. 117  LEEFER 2016 derived limits by using radio-frequency spectroscopy of dysprosium and atomic clock measurements. See their Fig. 1 for mass-dependent limits as well as limits on Yukawa-type couplings of the scalar to the electron and nucleons. 118  ANASTASSOPOULOS 2015 search for solar chameleons with CAST and derived limits on the chameleon coupling to photons and matter. See their Fig. 12 for the exclusion region. 119  ARIK 2015 is analogous to ARIK 2009, and search for solar axions for ${\mathit m}_{{{\mathit A}^{0}}}$ around 0.2 and 0.4 eV. See their Figs. 1 and 3 for the mass-dependent limits. 120  Based on OSQAR photon regeneration experiment. See their Fig. 6 for mass-dependent limits on scalar and pseudoscalar bosons. 121  BRAX 2015 derived limits on conformal and disformal couplings of a scalar to photons by searching for a chaotic absorption pattern in the X-ray and UV bands of the Hydra A galaxy cluster and a BL lac object, respectively. See their Fig. 8. 122  HASEBE 2015 look for an axion via a four-wave mixing process at quasi-parallel colliding laser beams. They also derived limits on a scalar coupling to photons $\mathit G_{{{\mathit S}} {{\mathit \gamma}} {{\mathit \gamma}}}$ $<$ $2.62 \times 10^{-4}$ GeV${}^{-1}$ at ${\mathit m}_{{{\mathit S}^{0}}}$ = 0.15 eV. See their Figs. 11 and 12 for mass-dependent limits. 123  MILLEA 2015 is similar to CADAMURO 2012, including the Planck data and the latest inferences of primordial deuterium abundance. See their Fig. 3 for mass-dependent limits. 124  VANTILBURG 2015 look for harmonic variations in the dyprosium transition frequency data, induced by coherent oscillations of the fine-structure constant due to dilaton-like dark matter, and set the limits, $\mathit G_{{{\mathit S}} {{\mathit \gamma}} {{\mathit \gamma}}}$ $<$ $6 \times 10^{-27}$ GeV${}^{-1}$ at ${\mathit m}_{{{\mathit S}^{0}}}$ = $6 \times 10^{-23}$ eV. See their Fig. 4 for mass-dependent limits between $1 \times 10^{-24}<$ ${\mathit m}_{{{\mathit S}^{0}}}<$ $1 \times 10^{-15}$ eV. 125  VINYOLES 2015 performed a global fit analysis based on helioseismology and solar neutrino observations. See their Fig. 9. 126  ARIK 2014 is similar to ARIK 2011. See their Fig. 2 for mass-dependent limits. 127  AYALA 2014 derived the limit from the helium-burning lifetime of horizontal-branch stars based on number counts in globular clusters. 128  DELLA-VALLE 2014 use the new PVLAS apparatus to set a limit on vacuum magnetic birefringence induced by axion-like particles. See their Fig. 6 for the mass-dependent limits. 129  EJLLI 2014 set limits on a product of primordial magnetic field and the axion mass using CMB distortion induced by resonant axion production from CMB photons. See their Fig.$~$1 for limits applying specifically to the DFSZ and KSVZ axion models. 130  PUGNAT 2014 is analogous to EHRET 2010. See their Fig. 5 for mass-dependent limits on scalar and pseudoscalar bosons. 131  REESMAN 2014 derive limits by requiring effects of axion-photon interconversion on gamma-ray spectra from distant blazars to be no larger than errors in the best-fit optical depth based on a certain extragalactic background light model. See their Fig. 5 for mass-dependent limits. 132  ABRAMOWSKI 2013A look for irregularities in the energy spectrum of the BL Lac object PKS 2155--304 measured by H.E.S.S. The limits depend on assumed magnetic field around the source. See their Fig. 7 for mass-dependent limits. 133  ARMENGAUD 2013 is analogous to AVIGNONE 1998. See Fig. 6 for the limit. 134  BETZ 2013 performed a microwave-based light shining through the wall experiment. See their Fig. 13 for mass-dependent limits. 135  FRIEDLAND 2013 derived the limit by considering blue-loop suppression of the evolution of red giants with $7 - 12$ solar masses. 136  MEYER 2013 attributed to axion-photon oscillations the observed excess of very high-energy ${{\mathit \gamma}}$-rays with respect to predictions based on extragalactic background light models. See their Fig.4 for mass-dependent lower limits for various magnetic field configurations. 137  WOUTERS 2013 look for irregularities in the X-ray spectrum of the Hydra cluster observed by Chandra. See their Fig. 4 for mass-dependent limits. 138  CADAMURO 2012 derived cosmological limits on $\mathit G_{{{\mathit A}}{{\mathit \gamma}}{{\mathit \gamma}}}$ for axion-like particles. See their Fig. 1 for mass-dependent limits. 139  PAYEZ 2012 derive limits from polarization measurements of quasar light (see their Fig.$~$3). The limits depend on assumed magnetic field strength in galaxy clusters. The limits depend on assumed magnetic field and electron density in the local galaxy supercluster. 140  ARIK 2011 search for solar axions using ${}^{3}\mathrm {He}$ buffer gas in CAST, continuing from the ${}^{4}\mathrm {He}$ version of ARIK 2009. See Fig.$~$2 for the exact mass-dependent limits. 141  ALPS is a photon regeneration experiment. See their Fig.$~$4 for mass-dependent limits on scalar and pseudoscalar bosons. 142  AHMED 2009A is analogous to AVIGNONE 1998. 143  ARIK 2009 is the ${}^{4}\mathrm {He}$ filling version of the CAST axion helioscope in analogy to INOUE 2002 and INOUE 2008. See their Fig.$~$7 for mass-dependent limits. 144  CHOU 2009 use the GammeV apparatus in the afterglow mode to search for chameleons, (pseudo)scalar bosons with a mass depending on the environment. For pseudoscalars they exclude at 3$\sigma $ the range $2.6 \times 10^{-7}$ GeV${}^{-1}<$ ${{\mathit G}}_{A{{\mathit \gamma}}{{\mathit \gamma}}}<$ $4.2 \times 10^{-6}$ GeV${}^{-1}$ for vacuum ${\mathit m}_{{{\mathit A}^{0}}}$ roughly below 6 meV for density scaling index exceeding 0.8. 145  GONDOLO 2009 use the all-flavor measured solar neutrino flux to constrain solar interior temperature and thus energy losses. 146  LIPSS photon regeneration experiment, assuming scalar particle ${{\mathit S}^{0}}$. See Fig.$~$4 for mass-dependent limits. 147  CHOU 2008 perform a variable-baseline photon regeneration experiment. See their Fig.$~$3 for mass-dependent limits. Excludes the PVLAS result of ZAVATTINI 2006. 148  FOUCHE 2008 is an update of ROBILLIARD 2007. See their Fig. 12 for mass-dependent limits. 149  INOUE 2008 is an extension of INOUE 2002 to larger axion masses, using the Tokyo axion helioscope. See their Fig. 4 for mass-dependent limits. 150  ZAVATTINI 2008 is an upgrade of ZAVATTINI 2006, see their Fig.$~$8 for mass-dependent limits. They now exclude the parameter range where ZAVATTINI 2006 had seen a positive signature. 151  ANDRIAMONJE 2007 looked for Primakoff conversion of solar axions in 9T superconducting magnet into X-rays. Supersedes ZIOUTAS 2005. 152  ROBILLIARD 2007 perform a photon regeneration experiment with a pulsed laser and pulsed magnetic field. See their Fig. 4 for mass-dependent limits. Excludes the PVLAS result of ZAVATTINI 2006 with a CL exceeding 99.9$\%$. 153  ZAVATTINI 2006 propagate a laser beam in a magnetic field and observe dichroism and birefringence effects that could be attributed to an axion-like particle. This result is now excluded by ROBILLIARD 2007, ZAVATTINI 2008, and CHOU 2008. 154  INOUE 2002 looked for Primakoff conversion of solar axions in 4T superconducting magnet into X$~$ray. 155  MORALES 2002B looked for the coherent conversion of solar axions to photons via the Primakoff effect in Germanium detector. 156  BERNABEI 2001B looked for Primakoff coherent conversion of solar axions into photons via Bragg scattering in NaI crystal in DAMA dark matter detector. 157  ASTIER 2000B looked for production of axions from the interaction of high-energy photons with the horn magnetic field and their subsequent re-conversion to photons via the interaction with the NOMAD dipole magnetic field. 158  MASSO 2000 studied limits on axion-proton coupling using the induced axion-photon coupling through the proton loop and CAMERON 1993 bound on the axion-photon coupling using optical rotation. They obtained the bound $\mathit g{}^{2}_{{{\mathit p}}}/4{{\mathit \pi}}<1.7 \times 10^{-9}$ for the coupling $\mathit g_{{{\mathit p}}}{{\overline{\mathit p}}}\gamma _{5}{{\mathit p}}\phi _{\mathit A}$. 159  AVIGNONE 1998 result is based on the coherent conversion of solar axions to photons via the Primakoff effect in a single crystal germanium detector. 160  Based on the conversion of solar axions to $\mathit X$-rays in a strong laboratory magnetic field. 161  Experiment based on proposal by MAIANI 1986. 162  Experiment based on proposal by VANBIBBER 1987. 163  LAZARUS 1992 experiment is based on proposal found in VANBIBBER 1989. 164  RUOSO 1992 experiment is based on the proposal by VANBIBBER 1987. 165  SEMERTZIDIS 1990 experiment is based on the proposal of MAIANI 1986. The limit is obtained by taking the noise amplitude as the upper limit. Limits extend to ${\mathit m}_{{{\mathit A}^{0}}}$ = $4 \times 10^{-3}$ where $\mathit G_{{{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}}}$ $<$ $1 \times 10^{-4}$ GeV${}^{-1}$.

References