16
1 Introduction
11. S. Alekhin et al., A facility to search for hidden particles at the CERN SPS: the SHiP physics
case. Rept. Prog. Phys. 79(12), 124201 (2016). arXiv:1504.04855 [hep-ph]. https://doi.org/10.
1088/0034-4885/79/12/124201
12. F. Curciarello, Review on dark photon. EPJ Web Conf. 118, 01008 (2016). https://doi.org/10.
1051/epjconf/201611801008
13. J. Alexander et al., Dark Sectors 2016 Workshop: Community Report (2016). arXiv:1608.08632
[hep-ph]. http://lss.fnal.gov/archive/2016/conf/fermilab-conf-16-421.pdf
14. J. Beacham et al., Physics beyond colliders at CERN: beyond the standard model working
group report. J. Phys. G 47(1), 010501 (2020). arXiv:1901.09966 [hep-ex]. https://doi.org/10.
1088/1361-6471/ab4cd2
15. B.A. Dobrescu, Massless gauge bosons other than the photon. Phys. Rev. Lett. 94, 151802
(2005). https://doi.org/10.1103/PhysRevLett.94.151802. arXiv:hep-ph/0411004 [hep-ph]
16. F. del Aguila, M. Masip, M. Perez-Victoria, Physical parameters and renormalization of U(1)-a
x U(1)-b models. Physis B456, 531–549 (1995). arXiv:hep-ph/9507455 [hep-ph]. https://doi.
org/10.1016/0550-3213(95)00511-6
17. D. Feldman, Z. Liu, P. Nath, The Stueckelberg Z-prime extension with kinetic mixing and
milli-charged dark matter from the hidden sector. Phys. Rev. D 75, 115001 (2007). https://doi.
org/10.1103/PhysRevD.75.115001. arXiv:hep-ph/0702123 [HEP-PH].
18. S. Davidson, S. Hannestad, G. Raffelt, Updated bounds on millicharged particles. JHEP 05,
003 (2000). https://doi.org/10.1088/1126-6708/2000/05/003. arXiv:hep-ph/0001179 [hep-ph]
19. H. Ruegg, M. Ruiz-Altaba, The Stueckelberg field. Int. J. Mod. Phys. A19, 3265–3348 (2004).
arXiv:hep-th/0304245 [hep-th]. https://doi.org/10.1142/S0217751X04019755
20. T. Appelquist, B.A. Dobrescu, A.R. Hopper, Nonexotic neutral Gauge Bosons. Phys. Rev.
D 68, 035012 (2003). https://doi.org/10.1103/PhysRevD.68.035012. arXiv:hep-ph/0212073
[hep-ph]
21. P. Galison, A. Manohar, Two Z’s or not two Z’s? Phys. Lett. 136B, 279–283 (1984). https://
doi.org/10.1016/0370-2693(84)91161-4
22. X.-G. He, G.C. Joshi, H. Lew, R.R. Volkas, Simplest Z-prime model. Phys. Rev. D 44, 2118–213
(1991). https://doi.org/10.1103/PhysRevD.44.2118
23. K.S. Babu, C.F. Kolda, J. March-Russell, Implications of generalized Z-Z-prime mixing.
Phys. Rev. D57, 6788–6792 (1998). arXiv:hep-ph/9710441 [hep-ph]. https://doi.org/10.1103/
PhysRevD.57.6788
24. H. Davoudiasl, H.-S. Lee, W.J. Marciano, ’Dark’ Z implications for parity violation, rare meson
decays, and higgs physics. Phys. Rev. D 85, 115019 (2012). https://doi.org/10.1103/PhysRevD.
85.115019. arXiv:1203.2947 [hep-ph]
25. J. Heeck, Unbroken B? L symmetry. Phys. Lett. B739, 256–262 (2014). arXiv:1408.6845
[hep-ph]. https://doi.org/10.1016/j.physletb.2014.10.067
26. M. Bauer, P. Foldenauer, J. Jaeckel, Hunting all the hidden photons. JHEP 07, 094 (2018).
https://doi.org/10.1007/JHEP07(2018)094. arXiv:1803.05466 [hep-ph]. [JHEP18,094(2020)]
27. P. Fayet, The light U boson as the mediator of a new force, coupled to a combination of Q, B, L
and dark matter. Eur. Phys. J. C77(1), 53 (2017). arXiv:1611.05357 [hep-ph]. https://doi.org/
10.1140/epjc/s10052-016-4568-9
28. T.G. Rizzo, Kinetic mixing, dark photons and an extra dimension. Part I. JHEP 07, 118 (2018).
arXiv:1801.08525 [hep-ph]. https://doi.org/10.1007/JHEP07(2018)118
29. E. Bertuzzo, S. Jana, P.A. Machado, R. Zukanovich Funchal, Neutrino masses and mixings dynamically generated by a light dark sector. Phys. Lett. B 791, 210–214 (2019).
arXiv:1808.02500 [hep-ph]. https://doi.org/10.1016/j.physletb.2019.02.023
30. R. Essig, P. Schuster, N. Toro, Probing dark forces and light hidden sectors at low-energy
e+e- colliders. Phys. Rev. D 80, 015003 (2009). https://doi.org/10.1103/PhysRevD.80.015003.
arXiv:0903.3941 [hep-ph]
31. S. Koren, R. McGehee, Freezing-in twin dark matter. Phys. Rev. D 101(5), 055024 (2020).
arXiv:1908.03559 [hep-ph]. https://doi.org/10.1103/PhysRevD.101.055024
32. T. Gherghetta, J. Kersten, K. Olive, M. Pospelov, Evaluating the price of tiny kinetic mixing. Phys. Rev. D 100(9) 095001 (2019). arXiv:1909.00696 [hep-ph]. https://doi.org/10.1103/
PhysRevD.100.095001
1 Introduction
11. S. Alekhin et al., A facility to search for hidden particles at the CERN SPS: the SHiP physics
case. Rept. Prog. Phys. 79(12), 124201 (2016). arXiv:1504.04855 [hep-ph]. https://doi.org/10.
1088/0034-4885/79/12/124201
12. F. Curciarello, Review on dark photon. EPJ Web Conf. 118, 01008 (2016). https://doi.org/10.
1051/epjconf/201611801008
13. J. Alexander et al., Dark Sectors 2016 Workshop: Community Report (2016). arXiv:1608.08632
[hep-ph]. http://lss.fnal.gov/archive/2016/conf/fermilab-conf-16-421.pdf
14. J. Beacham et al., Physics beyond colliders at CERN: beyond the standard model working
group report. J. Phys. G 47(1), 010501 (2020). arXiv:1901.09966 [hep-ex]. https://doi.org/10.
1088/1361-6471/ab4cd2
15. B.A. Dobrescu, Massless gauge bosons other than the photon. Phys. Rev. Lett. 94, 151802
(2005). https://doi.org/10.1103/PhysRevLett.94.151802. arXiv:hep-ph/0411004 [hep-ph]
16. F. del Aguila, M. Masip, M. Perez-Victoria, Physical parameters and renormalization of U(1)-a
x U(1)-b models. Physis B456, 531–549 (1995). arXiv:hep-ph/9507455 [hep-ph]. https://doi.
org/10.1016/0550-3213(95)00511-6
17. D. Feldman, Z. Liu, P. Nath, The Stueckelberg Z-prime extension with kinetic mixing and
milli-charged dark matter from the hidden sector. Phys. Rev. D 75, 115001 (2007). https://doi.
org/10.1103/PhysRevD.75.115001. arXiv:hep-ph/0702123 [HEP-PH].
18. S. Davidson, S. Hannestad, G. Raffelt, Updated bounds on millicharged particles. JHEP 05,
003 (2000). https://doi.org/10.1088/1126-6708/2000/05/003. arXiv:hep-ph/0001179 [hep-ph]
19. H. Ruegg, M. Ruiz-Altaba, The Stueckelberg field. Int. J. Mod. Phys. A19, 3265–3348 (2004).
arXiv:hep-th/0304245 [hep-th]. https://doi.org/10.1142/S0217751X04019755
20. T. Appelquist, B.A. Dobrescu, A.R. Hopper, Nonexotic neutral Gauge Bosons. Phys. Rev.
D 68, 035012 (2003). https://doi.org/10.1103/PhysRevD.68.035012. arXiv:hep-ph/0212073
[hep-ph]
21. P. Galison, A. Manohar, Two Z’s or not two Z’s? Phys. Lett. 136B, 279–283 (1984). https://
doi.org/10.1016/0370-2693(84)91161-4
22. X.-G. He, G.C. Joshi, H. Lew, R.R. Volkas, Simplest Z-prime model. Phys. Rev. D 44, 2118–213
(1991). https://doi.org/10.1103/PhysRevD.44.2118
23. K.S. Babu, C.F. Kolda, J. March-Russell, Implications of generalized Z-Z-prime mixing.
Phys. Rev. D57, 6788–6792 (1998). arXiv:hep-ph/9710441 [hep-ph]. https://doi.org/10.1103/
PhysRevD.57.6788
24. H. Davoudiasl, H.-S. Lee, W.J. Marciano, ’Dark’ Z implications for parity violation, rare meson
decays, and higgs physics. Phys. Rev. D 85, 115019 (2012). https://doi.org/10.1103/PhysRevD.
85.115019. arXiv:1203.2947 [hep-ph]
25. J. Heeck, Unbroken B? L symmetry. Phys. Lett. B739, 256–262 (2014). arXiv:1408.6845
[hep-ph]. https://doi.org/10.1016/j.physletb.2014.10.067
26. M. Bauer, P. Foldenauer, J. Jaeckel, Hunting all the hidden photons. JHEP 07, 094 (2018).
https://doi.org/10.1007/JHEP07(2018)094. arXiv:1803.05466 [hep-ph]. [JHEP18,094(2020)]
27. P. Fayet, The light U boson as the mediator of a new force, coupled to a combination of Q, B, L
and dark matter. Eur. Phys. J. C77(1), 53 (2017). arXiv:1611.05357 [hep-ph]. https://doi.org/
10.1140/epjc/s10052-016-4568-9
28. T.G. Rizzo, Kinetic mixing, dark photons and an extra dimension. Part I. JHEP 07, 118 (2018).
arXiv:1801.08525 [hep-ph]. https://doi.org/10.1007/JHEP07(2018)118
29. E. Bertuzzo, S. Jana, P.A. Machado, R. Zukanovich Funchal, Neutrino masses and mixings dynamically generated by a light dark sector. Phys. Lett. B 791, 210–214 (2019).
arXiv:1808.02500 [hep-ph]. https://doi.org/10.1016/j.physletb.2019.02.023
30. R. Essig, P. Schuster, N. Toro, Probing dark forces and light hidden sectors at low-energy
e+e- colliders. Phys. Rev. D 80, 015003 (2009). https://doi.org/10.1103/PhysRevD.80.015003.
arXiv:0903.3941 [hep-ph]
31. S. Koren, R. McGehee, Freezing-in twin dark matter. Phys. Rev. D 101(5), 055024 (2020).
arXiv:1908.03559 [hep-ph]. https://doi.org/10.1103/PhysRevD.101.055024
32. T. Gherghetta, J. Kersten, K. Olive, M. Pospelov, Evaluating the price of tiny kinetic mixing. Phys. Rev. D 100(9) 095001 (2019). arXiv:1909.00696 [hep-ph]. https://doi.org/10.1103/
PhysRevD.100.095001