Acknowledgements
The digital inclusion of some of the experimental limits in the figures was done by
means of WebPlotDigitizer.
1 Numerical results for some of the dark photon limits
were provided by the Darkcast package.
2
We would like to thank Tram Acuña, Andrea Celentano, Monica D’Onofrio,
Angelo Esposito, Oliver Fischer, Phil Ilten, Sam McDermott, Maxim Pospelov,
Diego Redigolo, Josh Ruderman, Piero Ullio, Alfredo Urbano and Mike Williams
for useful discussions and suggestions.
MF is affiliated to the Physics Department of the University of Trieste and the
Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy. MF and
EG are affiliated to the Institute for Fundamental Physics of the Universe (IFPU),
Trieste, Italy. The support of all these institutions is gratefully acknowledged. EG
thanks the Department of Theoretical Physics of CERN for its kind hospitality
during the preparation of this work.
1
Website: https://automeris.io/WebPlotDigitizer.
2
Website: https://gitlab.com/philten/darkcast.
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