1.3 Dark Matter and the Dark Photon
15
The dark-photon dark matter is non-relativistic and interacts with ordinary matter
mostly through the photo-electric process in which a photon (with energy m A ) is
captured by an atom, with atomic number Z , with a cross section given, for ordinary
photons, by
σ p.e. = 4α
4
√
2Z
5 8πr
2
e
3
m e
ω
7/2 ,
(1.33)
where ω is the photon energy and r e the classical radius of the electron r e = α/m e .
The cross section for the dark photons is that of ordinary photons rescaled by the
mixing parameter ε:
σ A = ε
2
σ p.e. .
(1.34)
This scenario is made accessible to the experiments by considering the rate of absorption of the dark photon by the detector [93, 94]:
A =
ρ A
m A
σ A v A ,
(1.35)
where the density ρ A is estimated from the relic density (or the flux from the Sun).
References
1. B. Holdom, Two U(1)’s and Epsilon charge shifts. Phys. Lett. 166B, 196–198 (1986). https://
doi.org/10.1016/0370-2693(86)91377-8
2. P. Fayet, Extra U(1)’s and new forces. Nucl. Phys. B 347, 743–768 (1990). https://doi.org/10.
1016/0550-3213(90)90381-M
3. P. Fayet, Effects of the Spin 1 partner of the Goldstino (Gravitino) on neutral current phenomenology. Phys. Lett. B 95, 285–289 (1980). https://doi.org/10.1016/0370-2693(80)904888
4. P. Fayet, On the search for a new Spin 1 Boson. Nucl. Phys. B 187, 184–204 (1981). https://
doi.org/10.1016/0550-3213(81)90122-X
5. L.B. Okun, Limits of electrodynamics: paraphotons? Sov. Phys. JETP 56, 502 (1982). [Zh.
Eksp. Teor. Fiz.83,892(1982)]
6. H. Georgi, P.H. Ginsparg, S.L. Glashow, Photon oscillations and the cosmic background radiation. Nature 306, 765–766 (1983). https://doi.org/10.1038/306765a0
7. J.L. Hewett et al., Fundamental Physics at the Intensity Frontier (2012). arXiv:1205.2671 [hepex]. http://lss.fnal.gov/archive/preprint/fermilab-conf-12-879-ppd.shtml. https://doi.org/10.
2172/1042577
8. R. Essig et al., Working group report: new light weakly coupled particles, in Proceedings, 2013
Community Summer Study on the Future of U.S. Particle Physics: Snowmass on the Mississippi
(CSS2013): Minneapolis, MN, USA, July 29–Au. 6, 2013 (2013). arXiv:1311.0029 [hep-ph].
http://www.slac.stanford.edu/econf/C1307292/docs/IntensityFrontier/NewLight-17.pdf
9. M. Raggi, V. Kozhuharov, Results and perspectives in dark photon physics. Riv. Nuovo Cim.
38(10), 449–505 (2015). https://doi.org/10.1393/ncr/i2015-10117-9
10. M.A. Deliyergiyev, Recent progress in search for dark sector signatures. Open Phys. 14(1),
281–303 (2016). arXiv:1510.06927 [hep-ph]. https://doi.org/10.1515/phys-2016-0034
15
The dark-photon dark matter is non-relativistic and interacts with ordinary matter
mostly through the photo-electric process in which a photon (with energy m A ) is
captured by an atom, with atomic number Z , with a cross section given, for ordinary
photons, by
σ p.e. = 4α
4
√
2Z
5 8πr
2
e
3
m e
ω
7/2 ,
(1.33)
where ω is the photon energy and r e the classical radius of the electron r e = α/m e .
The cross section for the dark photons is that of ordinary photons rescaled by the
mixing parameter ε:
σ A = ε
2
σ p.e. .
(1.34)
This scenario is made accessible to the experiments by considering the rate of absorption of the dark photon by the detector [93, 94]:
A =
ρ A
m A
σ A v A ,
(1.35)
where the density ρ A is estimated from the relic density (or the flux from the Sun).
References
1. B. Holdom, Two U(1)’s and Epsilon charge shifts. Phys. Lett. 166B, 196–198 (1986). https://
doi.org/10.1016/0370-2693(86)91377-8
2. P. Fayet, Extra U(1)’s and new forces. Nucl. Phys. B 347, 743–768 (1990). https://doi.org/10.
1016/0550-3213(90)90381-M
3. P. Fayet, Effects of the Spin 1 partner of the Goldstino (Gravitino) on neutral current phenomenology. Phys. Lett. B 95, 285–289 (1980). https://doi.org/10.1016/0370-2693(80)904888
4. P. Fayet, On the search for a new Spin 1 Boson. Nucl. Phys. B 187, 184–204 (1981). https://
doi.org/10.1016/0550-3213(81)90122-X
5. L.B. Okun, Limits of electrodynamics: paraphotons? Sov. Phys. JETP 56, 502 (1982). [Zh.
Eksp. Teor. Fiz.83,892(1982)]
6. H. Georgi, P.H. Ginsparg, S.L. Glashow, Photon oscillations and the cosmic background radiation. Nature 306, 765–766 (1983). https://doi.org/10.1038/306765a0
7. J.L. Hewett et al., Fundamental Physics at the Intensity Frontier (2012). arXiv:1205.2671 [hepex]. http://lss.fnal.gov/archive/preprint/fermilab-conf-12-879-ppd.shtml. https://doi.org/10.
2172/1042577
8. R. Essig et al., Working group report: new light weakly coupled particles, in Proceedings, 2013
Community Summer Study on the Future of U.S. Particle Physics: Snowmass on the Mississippi
(CSS2013): Minneapolis, MN, USA, July 29–Au. 6, 2013 (2013). arXiv:1311.0029 [hep-ph].
http://www.slac.stanford.edu/econf/C1307292/docs/IntensityFrontier/NewLight-17.pdf
9. M. Raggi, V. Kozhuharov, Results and perspectives in dark photon physics. Riv. Nuovo Cim.
38(10), 449–505 (2015). https://doi.org/10.1393/ncr/i2015-10117-9
10. M.A. Deliyergiyev, Recent progress in search for dark sector signatures. Open Phys. 14(1),
281–303 (2016). arXiv:1510.06927 [hep-ph]. https://doi.org/10.1515/phys-2016-0034