Hidden Photons: Kinetic Mixing Parameter Limits INSPIRE search

Hidden photons limits are listed for the first time, including only the most recent papers. Suggestions for previous important results are welcome. Limits are on the kinetic mixing parameter $\chi $ which is defined by the Lagrangian $\mathit L$ = $\text{-}{1\over 4}{{\mathit F}}_{ {{\mathit \mu}} {{\mathit \nu}} }{{\mathit F}}{}^{ {{\mathit \mu}} {{\mathit \nu}} }$ $−{1\over 4}{{\mathit F}}{}^{'}_{ {{\mathit \mu}} {{\mathit \nu}} }{{\mathit F}}{}^{' {{\mathit \mu}} {{\mathit \nu}} }$ $\text{-}{\chi \over 2}{{\mathit F}}_{ {{\mathit \mu}} {{\mathit \nu}} }{{\mathit F}}{}^{' {{\mathit \mu}} {{\mathit \nu}} }$ + ${{{\mathit m}}{}^{2}_{{{\mathit \gamma}^{\,'}}}\over 2}{{\mathit A}}{}^{'}_{{{\mathit \mu}}}{{\mathit A}}{}^{'{{\mathit \mu}}}$, where ${{\mathit A}_{{\mu}}}$ and ${{\mathit A}_{{\mu}}^{\,'}}$ are the photon and hidden-photon fields with field strengths ${{\mathit F}}_{ {{\mathit \mu}} {{\mathit \nu}} }$ and ${{\mathit F}}{}^{'}_{ {{\mathit \mu}} {{\mathit \nu}} }$, respectively, and is the hidden-photon mass.
VALUE CL% DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
$<3.1 \times 10^{-14}$ 90 1
ABGRALL
2017
HPGE ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 11.8 keV
$<6 \times 10^{-4}$ 90 2
ABLIKIM
2017AA
BES3 ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $1.5 - 3.4$ GeV
$<7 \times 10^{-15}$ 90 3
ANGLOHER
2017
CRES ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $0.3 - 0.7$ keV
$<1.2 \times 10^{-4}$ 90 4
BANERJEE
2017
NA64 ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $0.002 - 0.4$ GeV
$<2 \times 10^{-11}$ 5
CHANG
2017
ASTR ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 15 MeV
$<4.5 \times 10^{-3}$ 90 6
DUBININA
2017
EMUL ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $1.1 - 24$ MeV
$<4 \times 10^{-4}$ 90 7
LEES
2017E
BABR ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 4.7 GeV
8
AAD
2016AG
ATLS ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $0.1 - 2$ GeV
$<4.4 \times 10^{-4}$ 90 9
ANASTASI
2016
KLOE ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $527 - 987$ MeV
$<1.7 \times 10^{-6}$ 95 10
KHACHATRYAN
2016
CMS ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 2 GeV
$<7 \times 10^{-4}$ 90 11
LEES
2016F
BABR ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $0.212 - 10$ GeV
$<0.04$ 95 12
AAD
2015CD
ATLS ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $15 - 55$ GeV
$<1.4 \times 10^{-3}$ 90 13
ADARE
2015
${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $30 - 90$ MeV
14
AN
2015A
${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 12 eV - 40 keV
15
ANASTASI
2015
KLOE ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 2${\mathit m}_{{{\mathit \mu}}}$ - 1 GeV
$<1.7 \times 10^{-3}$ 90 16
ANASTASI
2015A
KLOE ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $5 - 320$ MeV
$<4.2 \times 10^{-4}$ 90 17
BATLEY
2015A
NA48 ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 36 MeV
18
JAEGLE
2015
BELL ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $0.1 - 3.5$ GeV
$<3 \times 10^{-13}$ 19
KAZANAS
2015
ASTR ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 2${\mathit m}_{{{\mathit e}}}$ $-$ 100 MeV
20
SUZUKI
2015
${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $1.9 - 4.3$ eV
$<2.3 \times 10^{-13}$ 100 21
VINYOLES
2015
ASTR ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 8 eV
22
ABE
2014F
XMAS ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $40 - 120$ keV
$<1.8 \times 10^{-3}$ 90 23
AGAKISHIEV
2014
HDES ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 63 MeV
$<9.0 \times 10^{-4}$ 90 24
BABUSCI
2014
KLOE ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 969 MeV
25
BATELL
2014
BDMP ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $10^{-3} - 1$ GeV
$<1.3 \times 10^{-7}$ 95 26
BLUEMLEIN
2014
BDMP ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 0.6 GeV
$<3 \times 10^{-18}$ 27
FRADETTE
2014
COSM ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $50 - 300$ MeV
$<3.5 \times 10^{-4}$ 90 28
LEES
2014J
BABR ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 0.2 GeV
$<9 \times 10^{-4}$ 95 29
MERKEL
2014
A1 ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $40 - 300$ MeV
$<3 \times 10^{-15}$ 30
AN
2013B
ASTR ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 2 keV
$<7 \times 10^{-14}$ 31
AN
2013C
XE10 ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 100 eV
$<8 \times 10^{-4}$ 32
DIAMOND
2013
BDMP ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $30 - 250$ MeV
$<2.2 \times 10^{-13}$ 33
HORVAT
2013
HPGE ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 230 eV
$<8.06 \times 10^{-5}$ 95 34
INADA
2013
LSW ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 0.04 eV$−$26 keV
$<2 \times 10^{-10}$ 95 35
MIZUMOTO
2013
${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 1 eV
$<1.7 \times 10^{-7}$ 36
PARKER
2013
LSW ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 53 $\mu $eV
$<5.32 \times 10^{-15}$ 37
PARKER
2013
${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 53 $\mu $eV
$<1 \times 10^{-15}$ 38
REDONDO
2013
ASTR ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 2 keV
$<8 \times 10^{-8}$ 90 39
GNINENKO
2012A
BDMP ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $1 - 135$ MeV
$<1 \times 10^{-7}$ 90 40
GNINENKO
2012B
CHRM ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $1 - 500$ MeV
$<1 \times 10^{-3}$ 90 41
ABRAHAMYAN
2011
${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $175 - 250$ MeV
$<9 \times 10^{-8}$ 95 42
BLUEMLEIN
2011
BDMP ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 70 MeV
$<1 \times 10^{-7}$ 43
BJORKEN
2009
BDMP ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $2 - 400$ MeV
$<5 \times 10^{-9}$ 44
BJORKEN
2009
ASTR ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $2 - 50$ MeV
1  ABGRALL 2017 is analogous to ABE 2014F using the MAJORANA DEMONSTRATOR. See their Fig. 3 for limits between 6 keV $<$ ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ $<$ 97 keV.
2  ABLIKIM 2017AA look for ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}^{\,'}}$ ( ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ or ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ ) . Limits between $10^{-3}$ and $10^{-4}$ are obtained (see their Fig. 3).
3  ANGLOHER 2017 is analogous to ABE 2014F. The quoted limit is at ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 0.7 keV. See their Fig. 8 for mass-dependent limits.
4  BANERJEE 2017 look for invisible decays of hidden photons produced in the reaction ${{\mathit e}^{-}}$ ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}^{-}}{{\mathit Z}}{{\mathit \gamma}^{\,'}}$ . The quoted limit applies to ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 2 MeV. See their Fig. 3 for mass-dependent limits.
5  CHANG 2017 examine the hidden photon emission from SN1987A, including the effects of finite temperature and density on $\chi $ and obtain limits $\chi $ (${\mathit m}_{{{\mathit \gamma}^{\,'}}}$/MeV) ${ {}\lesssim{} }$ $3 \times 10^{-9}$ for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ $<$ 15 MeV and $\chi $ ${ {}\lesssim{} }$ $10^{-9}$ for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $15 - 120$ MeV.
6  DUBININA 2017 look for ${{\mathit \mu}^{+}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\overline{\mathit \nu}}_{{\mu}}}{{\mathit \nu}_{{e}}}{{\mathit \gamma}^{\,'}}$ ( ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ ) in a nuclear photoemulsion. The quoted limit applies to ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 1.1 MeV. Limits between $4.5 \times 10^{-3}$ and are obtained (see their Fig. 3).
7  LEES 2017E look for invisible decays of hidden photons produced in the reaction ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}^{\,'}}$ . See their Fig. 5 for limits in the mass range ${\mathit m}_{{{\mathit \gamma}^{\,'}}}{}\leq{}$ 8 GeV.
8  AAD 2016AG look for hidden photons promptly decaying into collimated electrons and/or muons, assuming that they are produced in the cascade decays of squarks or the Higgs boson. See their Fig. 10 and Fig.13 for their limits on the cross section times branching fractions.
9  ANASTASI 2016 look for the decay ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit \pi}^{+}}$ ${{\mathit \pi}^{-}}$ in the reaction ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}^{\,'}}$ . Limits between $4.3 \times 10^{-3}$ and $4.4 \times 10^{-4}$ are obtained for 527 $<$ ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ $<$ 987 MeV (see their Fig. 9).
10  KHACHATRYAN 2016 look for ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ in a dark SUSY scenario where the SM-like Higgs boson decays into a pair of the visible lightest neutralinos with mass 10 GeV, both of which decay into ${{\mathit \gamma}^{\,'}}$ and a hidden neutralino with mass 1 GeV. See the right panel in their Fig. 2.
11  LEES 2016F looked for a hidden photon coupled only to the second and third generations of leptons in the reaction ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \gamma}^{\,'}}$ ( ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ ) using data collected by BABAR detector, and derived limits on the hidden photon gauge coupling as low as $7 \times 10^{-4}$ for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $0.212 - 10$ GeV. See their Fig. 5 for the mass-dependent limits.
12  AAD 2015CD look for ${{\mathit H}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit \gamma}^{\,'}}$ $\rightarrow$ 4 ${{\mathit \ell}}$ with the ATLAS detector at LHC and find $\chi $ $<$ $4 - 17$ for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $15 - 55$ GeV. See their Fig. 6.
13  ADARE 2015 look for a hidden photon in ${{\mathit \pi}^{0}}$, ${{\mathit \eta}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit e}^{+}}{{\mathit e}^{-}}$ at the PHENIX experiment. See their Fig. 4 for mass-dependent limits.
14  AN 2015A derived limits from the absence of ionization signals in the XENON10 and XENON100 experiments, assuming hidden photons constitute all the local dark matter. Their best limit is $\chi $ $<$ $1.3 \times 10^{-15}$ at ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = 18 eV. See their Fig. 1 for mass-dependent limits.
15  ANASTASI 2015 look for a production of a hidden photon and a hidden Higgs boson with the KLOE detector at DA$\Phi $NE, where the hidden photon decays into a pair of muons and the hidden Higgs boson lighter than ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ escape detection. See their Figs. 6 and 7 for mass-dependent limits on a product of the hidden fine structure constant and the kinetic mixing.
16  ANASTASI 2015A look for the decay ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ in the reaction ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}{{\mathit \gamma}}$ . Limits between $1.7 \times 10^{-3}$ and $0.01$ are obtained for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $5 - 320$ MeV (see their Fig. 7).
17  BATLEY 2015A look for ${{\mathit \pi}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}^{\,'}}$ ( ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ ) at the NA48/2 experiment. Limits between $4.2 \times 10^{-4}$ and $8.8 \times 10^{-3}$ are obtained for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $9 - 120$ MeV (see their Fig. 4).
18  JAEGLE 2015 look for the decay ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ , or ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ in the dark Higgstrahlung channel, ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \gamma}^{\,'}}{{\mathit H}^{\,'}}$ ( ${{\mathit H}^{\,'}}$ $\rightarrow$ ${{\mathit \gamma}^{\,'}}{{\mathit \gamma}^{\,'}}$ ) at the BELLE experiment. They set limits on a product of the branching fraction and the Born cross section as well as a product of the hidden fine structure constant and the kinetic mixing. See their Figs. 3 and 4.
19  KAZANAS 2015 set limits by studying the decay of hidden photons ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ inside and near the progenitor star of SN1987A. See their Fig. 6 for mass-dependent limits.
20  SUZUKI 2015 looked for hidden-photon dark matter with a dish antenna and derived limits assuming they constitute all the local dark matter. Their limits are $\chi $ $<$ $6 \times 10^{-12}$ for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $1.9 - 4.3$ eV. See their Fig. 7 for mass-dependent limits.
21  VINYOLES 2015 performed a global fit analysis based on helioseismology and solar neutrino observations, and set the limits $\chi {\mathit m}_{{{\mathit \gamma}^{\,'}}}$ $<$ $1.8 \times 10^{-12}$ eV for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $3 \times 10^{-5} - 8$ eV. See their Fig. 11.
22  ABE 2014F look for the photoelectric-like interaction in the XMASS detector assuming the hidden photon constitutes all the local dark matter. Limits between $2 \times 10^{-13}$ and $1 \times 10^{-12}$ are obtained. See their Fig. 3 for mass-dependent limits.
23  AGAKISHIEV 2014 look for hidden photons ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ at the HADES experiment, and set limits on ${{\mathit \chi}}$ for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $0.02 - 0.6$ GeV. See their Fig. 5 for mass-dependent limits.
24  BABUSCI 2014 look for the decay ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit \mu}^{+}}$ ${{\mathit \mu}^{-}}$ in the reaction ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \gamma}}$ . Limits between $4 \times 10^{-3}$ and $9.0 \times 10^{-4}$ are obtained for 520 MeV $<$ ${\mathit m}_{{{\mathit \gamma}^{\,'}}}<$ 980 MeV (see their Fig. 7).
25  BATELL 2014 derived limits from the electron beam dump experiment at SLAC (E-137) by searching for events with recoil electrons by sub-GeV dark matter produced from the decay of the hidden photon. Limits at the level of are obtained for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ = $10^{-3} - 1$ GeV, depending on the dark matter mass and the hidden gauge coupling (see their Fig. 2).
26  BLUEMLEIN 2014 analyzed the beam dump data taken at the U-70 accelerator to look for ${{\mathit \gamma}^{\,'}}$-bremsstrahlung and the subsequent decay into muon pairs and hadrons. See their Fig. 4 for mass-dependent excluded region.
27  FRADETTE 2014 studied effects of decay of relic hidden photons on BBN and CMB to set constraints on very small values of the kinetic mixing. See their Figs. 4 and 7 for mass-dependent excluded regions.
28  LEES 2014J look for hidden photons in the reaction ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}^{\,'}}$ ( ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , ${{\mathit \mu}^{+}}$ ${{\mathit \mu}^{-}}$ ). Limits at the level of $10^{-4} - 10^{-3}$ are obtained for 0.02 GeV $<$ ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ $<$ 10.2 GeV. See their Fig. 4 for mass-dependent limits.
29  MERKEL 2014 look for ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ at the A1 experiment at the Mainz Microtron (MAMI). See their Fig. 3 for mass-dependent limits.
30  AN 2013B examined the stellar production of hidden photons, correcting an important error of the production rate of the longitudinal mode which now dominates. See their Fig. 2 for mass-dependent limits based on solar energy loss.
31  AN 2013C use the solar flux of hidden photons to set a limit on the atomic ionization rate in the XENON10 experiment. They find $\chi $ ${\mathit m}_{{{\mathit \gamma}^{\,'}}}$ $<$ $3 \times 10^{-12}$ eV for ${\mathit m}_{{{\mathit \gamma}^{\,'}}}<$ 1 eV. See their Fig. 2 for mass-dependent limits.
32  DIAMOND 2013 analyzed the beam dump data taken at the SLAC millicharge experiment to constrain a hidden photon invisibly decaying into lighter long-lived particles, which undergo elastic scattering off nuclei in the detector. Limits between $8 \times 10^{-4} - 0.02$ are obtained. The quoted limit is applied when the dark gauge coupling is set equal to the electromagnetic coupling. See their Fig.4 for mass-dependent limits.
33  HORVAT 2013 look for hidden-photo-electric effect in HPGe detectors induced by solar hidden photons. See their Fig. 3 for mass-dependent limits.
34  INADA 2013 search for hidden photons using an intense X-ray beamline at SPring-8. See their Fig. 4 for mass-dependent limits.
35  MIZUMOTO 2013 look for solar hidden photons. See their Fig. 5 for mass-dependent limits.
36  PARKER 2013 look for hidden photons using a cryogenic resonant microwave cavity. See their Fig.5 for mass-dependent limits.
37  PARKER 2013 derived a limit for the hidden photon CDM with a randomly oriented hidden photon field.
38  REDONDO 2013 examined the solar emission of hidden photons including the enhancement factor for the longitudinal mode pointed out by AN 2013B, and also updated stellar-energy loss arguments. See their Fig.3 for mass-dependent limits, including a review of the currently best limits from other arguments.
39  GNINENKO 2012A obtained bounds on B( ${{\mathit \pi}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}^{\,'}}$ ) $\cdot{}$ B( ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ ) from the NOMAD and PS191 neutrino experiments, and derived limits between $8 \times 10^{-8} - 2 \times 10^{-4}$. See their Fig.4 for mass-dependent excluded regions.
40  GNINENKO 2012B used the data taken at the CHARM experiment to constrain the decay, ${{\mathit \eta}}({{\mathit \eta}^{\,'}}$) $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}^{\,'}}$ ( ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ ), and derived limits between $1 \times 10^{-7} - 1 \times 10^{-4}$. See their Fig.4 for mass-dependent excluded region.
41  ABRAHAMYAN 2011 look for ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ in the electron-nucelon fixed-target experiment at the Jefferson Laboratory (APEX). See their Fig. 5 for mass-dependent limits.
42  BLUEMLEIN 2011 analyzed the beam dump data taken at the U-70 accelerator to look for ${{\mathit \pi}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}^{\,'}}$ ( ${{\mathit \gamma}^{\,'}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ ). See their Fig. 5 for mass-dependent limits.
43  BJORKEN 2009 analyzed the beam dump data taken at E137, E141, and E774 to constrain a hidden photon produced by bremsstrahlung, subsequently decaying into ${{\mathit e}^{+}}{{\mathit e}^{-}}$ , and derived limits between $10^{-7}$ and . See their Fig. 1 for mass-dependent excluded region.
44  BJORKEN 2009 required the energy loss in the ${{\mathit \gamma}^{\,'}}$ emission from the core of SN1987A not to exceed $10^{53}$ erg/s, and derived limits between $5 \times 10^{-9}$ and $2 \times 10^{-6}$. See their Fig. 1 for mass-dependent excluded region.
  References:
ABGRALL 2017
PRL 118 161801 New limits on Bosonic Dark Matter, Solar Axions, Pauli Exclusion Principle Violation, and Electron Decay from the Majorana Demonstrator
ABLIKIM 2017AA
PL B774 252 Dark Photon Search in the Mass Range between 1.5 and 3.4 ${\mathrm {GeV/}}\mathit c{}^{2}$
ANGLOHER 2017
EPJ C77 299 Dark-Photon Search using Data from CRESST-II Phase 2
BANERJEE 2017
PRL 118 011802 Search for Invisible Decays of sub-GeV Dark Photons in Missing-Energy Events at the CERN SPS
CHANG 2017
JHEP 1701 107 Revisiting Supernova 1987A Constraints on Dark Photons
DUBININA 2017
PAN 80 461 Search for a Light Dark Photon in Muonium Decay
LEES 2017E
PRL 119 131804 Search for Invisible Decays of a Dark Photon Produced in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at BaBar
AAD 2016AG
JHEP 1602 062 A Search for Prompt Lepton-Jets in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 8 TeV with the ATLAS Detector
ANASTASI 2016
PL B757 356 Limit on the Production of a New Vector Boson in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit U}}{{\mathit \gamma}}$ , ${{\mathit U}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ with the KLOE Experiment
KHACHATRYAN 2016
PL B752 146 A Search for Pair Production of New Light Bosons Decaying into Muons
LEES 2016F
PR D94 011102 Search for a Muonic Dark Force at BABAR
AAD 2015CD
PR D92 092001 Search for New Light Gauge Bosons in Higgs Boson Decays to Four-Lepton Final States in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 8 TeV with the ATLAS Detector at the LHC
ADARE 2015
PR C91 031901 Search for Dark Photons from Neutral Meson Decays in ${{\mathit p}}$ + ${{\mathit p}}$ and ${{\mathit d}}$ + ${}^{}\mathrm {Au}$ Collisions at $\sqrt {s_{NN} }$ = 200 GeV
AN 2015A
PL B747 331 Direct Detection Constraints on Dark Photon Dark Matter
ANASTASI 2015
PL B747 365 Search for Dark Higgsstrahlung in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ and Missing Energy Events with the KLOE Experiment
ANASTASI 2015A
PL B750 633 Limit on the Production of a Low-Mass Vector Boson in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit U}}{{\mathit \gamma}}$ , ${{\mathit U}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ with the KLOE Experiment
BATLEY 2015A
PL B746 178 Search for the Dark Photon in ${{\mathit \pi}^{0}}$ Decays
JAEGLE 2015
PRL 114 211801 Search for the Dark Photon and the Dark Higgs Boson at Belle
KAZANAS 2015
NP B890 17 Supernova Bounds on the Dark Photon using its Electromagnetic Decay
SUZUKI 2015
JCAP 1509 042 Experimental Search for Hidden Photon CDM in the eV Mass Range with a Dish Antenna
VINYOLES 2015
JCAP 1510 015 New Axion and Hidden Photon Constraints from a Solar Data Global Fit
ABE 2014F
PRL 113 121301 Search for Bosonic Superweakly Interacting Massive Dark Matter Particles with the XMASS-I Detector
AGAKISHIEV 2014
PL B731 265 Searching a Dark Photon with HADES
BABUSCI 2014
PL B736 459 Search for Light Vector Boson Production in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{{\mathit \gamma}}$ Interactions with the KLOE Experiment
BATELL 2014
PRL 113 171802 Strong Constraints on Sub-GeV Dark Sectors from SLAC Beam Dump E137
BLUEMLEIN 2014
PL B731 320 New Exclusion Limits on Dark Gauge Forces from Proton Bremsstrahlung in Beam-Dump Data
FRADETTE 2014
PR D90 035022 Cosmological Constraints on Very Dark Photons
LEES 2014J
PRL 113 201801 Search for a Dark Photon in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at BaBar
MERKEL 2014
PRL 112 221802 Search at the Mainz Microtron for Light Massive Gauge Bosons Relevant for the Muon $\mathit g−$2 Anomaly
AN 2013C
PRL 111 041302 Dark Matter Detectors as Dark Photon Helioscopes
AN 2013B
PL B725 190 New Stellar Constraints on Dark Photons
DIAMOND 2013
PRL 111 221803 Searching for Light Dark Matter with the SLAC Millicharge Experiment
HORVAT 2013
PL B721 220 Constraining Solar Hidden Photons Using HPGe Detector
INADA 2013
PL B722 301 Results of a Search for Paraphotons with Intense X-ray Beams at SPring-8
MIZUMOTO 2013
JCAP 1307 013 Experimental Search for Solar Hidden Photons in the eV Energy Range using Kinetic Mixing with Photons
PARKER 2013
PR D88 112004 Cryogenic Resonant Microwave Cavity Searches for Hidden Sector Photons
REDONDO 2013
JCAP 1308 034 Solar Constraints on Hidden Photons re-Visited
GNINENKO 2012A
PR D85 055027 Stringent Limits on the ${{\mathit \pi}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit X}}$ , ${{\mathit X}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Decay from Neutrino Experiments and Constraints on New Light Gauge Bosons
GNINENKO 2012B
PL B713 244 Constraints on sub-GeV Hidden Sector Gauge Bosons from a Search for Heavy Neutrino Decays
ABRAHAMYAN 2011
PRL 107 191804 Search for a New Gauge Boson in Electron-Nucleus Fixed-Target Scattering by the APEX Experiment
BLUEMLEIN 2011
PL B701 155 New Exclusion Limits for Dark Gauge Forces from Beam-Dump Data
BJORKEN 2009
PR D80 075018 New Fixed-Target Experiments to Search for Dark Gauge Forces
KHACHATRYAN 2016BB
JHEP 1609 056 Erratum tp KHACHATRYAN 2016AV: Search for Direct Pair Production of Scalar Top Quarks in the Single- and Dilepton Channels in Proton-Proton Collisions at $\sqrt {s }$ = 8 TeV