Long-lived vectors from electromagnetic cascades at SHiP
Published in Journal of High Energy Physics (JHEP), 2025
We simulate dark-vector, V, production from electromagnetic cascades at the recently approved SHiP experiment. The cascades (initiated by photons from π⁰ → γγ) can lead to 3–4 orders of magnitude increase of the event rate relative to using primary production alone. We provide new SHiP sensitivity projections for dark photons and electrophilic gauge bosons, which are significantly improved compared to previous literature. The main gain in sensitivity occurs for long-lived dark vectors with masses below ~ 50 − 300 MeV. The dominant production mode in this parameter space is low-energy annihilation e⁺e⁻ → V (γ). This motivates a detailed study of backgrounds and efficiencies in the SHiP experiment for sub-GeV signals.
arXiv: 2412.01880
DOI: 10.1007/JHEP02(2025)107
Report Numbers: MI-HET-843, CALT-TH/2024-036, FERMILAB-PUB-24-0869-T
Recommended citation: Tao Zhou, Ryan Plestid, Kevin J. Kelly, Nikita Blinov, Patrick J. Fox. (2025). "Long-lived vectors from electromagnetic cascades at SHiP." JHEP. 02 (2025) 107.
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