Search for long-lived dark photons from hidden radiation at the LHC
- 1National Taiwan Normal University
- 2National Taiwan University
- 3Phenikaa University
Abstract
A bstract : We investigate a novel production mechanism for long-lived dark photons at the LHC, arising from hidden radiation emitted from χ in Z→ χ̅χ Z → χ ¯ χ decays, where χ is a fermionic dark matter candidate. The effective Zχχ coupling is generated radiatively through one-loop diagrams involving the top quark and a new colored scalar. We show that dark photons produced via this hidden radiation channel can dominate over the conventional sources — meson decays and proton bremsstrahlung — across wide regions of parameter space, particularly for small kinetic mixing and dark photon masses well above the GeV scale. Using this enhanced production mechanism, we analyze the sensitivity of dedicated long-lived particle detectors, including FASER2, FACET, and MATHUSLA. We find that these experiments can significantly surpass existing bounds, probing regions of dark photon parameter space consistent with the observed dark matter relic abundance and inaccessible in conventional dark photon scenarios.
Related
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- Search for Neutrino-Produced Long-Lived Particles Using the SBND Cosmic Ray Tagger Beam Telescope
BibTeX
@article{chen2026search,
title = {{Search for long-lived dark photons from hidden radiation at the LHC}},
author = {Chuan-Ren Chen and Van Que Tran},
journal = {Journal of High Energy Physics},
year = {2026},
month = oct,
doi = {10.1007/jhep10(2026)033},
url = {https://link.springer.com/10.1007/JHEP10(2026)033},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Search for long-lived dark photons from hidden radiation at the LHC
AU - Chuan-Ren Chen
AU - Van Que Tran
PY - 2026
DA - 2026/10/02
JO - Journal of High Energy Physics
DO - 10.1007/jhep10(2026)033
UR - https://link.springer.com/10.1007/JHEP10(2026)033
AB - A bstract : We investigate a novel production mechanism for long-lived dark photons at the LHC, arising from hidden radiation emitted from χ in Z→ χ̅χ Z → χ ¯ χ decays, where χ is a fermionic dark matter candidate. The effective Zχχ coupling is generated radiatively through one-loop diagrams involving the top quark and a new colored scalar. We show that dark photons produced via this hidden radiation channel can dominate over the conventional sources — meson decays and proton bremsstrahlung — across wide regions of parameter space, particularly for small kinetic mixing and dark photon masses well above the GeV scale. Using this enhanced production mechanism, we analyze the sensitivity of dedicated long-lived particle detectors, including FASER2, FACET, and MATHUSLA. We find that these experiments can significantly surpass existing bounds, probing regions of dark photon parameter space consistent with the observed dark matter relic abundance and inaccessible in conventional dark photon scenarios.
SN - 1029-8479
ER -