2025/11/04 by Carrasco, Juliana, Kulkarni, Suchita, Liu, Wei +2
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies
paper · doi:10.48550/arxiv.2511.02918
openalex publication_date 2025/11/04 · openalex created_date 2025/11/07 · openalex updated_date 2026/07/28
We propose a new class of dark-shower signatures in Standard Model extensions featuring Hidden Valleys or dark sectors coupled through an s-channel mediator. In this framework, unstable dark pions appear as long-lived particles (LLPs), with their lifetimes treated as free parameters. The resulting signatures, which we term semi-visible emerging jets (SVEJ), continuously interpolate between the established semi-visible and emerging jet regimes. We outline an analysis strategy optimized for dark pion lifetimes of order O(10) mm, and reinterpret existing LLP searches targeting lifetimes of O(100)-O(1000) mm. Our proposed SVEJ search, exploiting the current ATLAS emerging-jet trigger, achieves sensitivity to cross sections of O(0.1) fb for lifetimes around O(10) mm. Finally, we advocate a more detailed study, including hadronization uncertainties and detector-level effects.