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ANUBIS detector and its sensitivity to neutral long-lived particles

Thomas Adolphus20, Giulio Aielli18, Jahanzeb Akhtar8,20, Arun Atwal20, Martin Bauer5, Rachel Bentham13,20, Oleg Brandt1, Jude Burling20, Jon Burr20 et al. (ANUBIS Collaboration*)

Jon Burr20, Patrick Collins20, Louie Dartmoor Corpe3, Matthew Coxon20, Jonas Dej1, Sofie Nordahl Erner23, Cayetano Fernandez Ruiz1, Jindrich Jelinek4,7,20, Oliver Kortner17, Hubert Kroha17, Lawrence Lee, Jr.19,22, Christopher Lester1, Yingshan Liang1, Kaijia Liu20, Anna Mullin1, Christian Ohm16, David Peng20, Luca Pizzimento9, Ludovico Pontecorvo2, Giorgia Proto17, Théo Reymermier12,20, Michael Revering1, Elisa Ritz21, Thomas P. Satterthwaite14,15,20, Aashaq Shah1, Sinem Simsek11, Daniel Soyk17, Tom Spencer8,20, Paul Swallow1, Balint Szepfalvi20, Noshin Tarannum7,20, Olivia Valentino10,20, Julian Wack1, Yanglin Wan6,20, Peng Wang20, Esperanza Winter Lopez20, Monami Yoshioka20, and Yingchang Zhang1 (ANUBIS Collaboration*)

  • *Contact author: anubis-publications@cern.ch
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Phys. Rev. D 114, 092003 – Published 6 November, 2026

DOI: https://doi.org/10.1103/kd5j-d4fv

Abstract

Long-lived particles (LLPs), i.e., particles with macroscopic lifetimes τ>10  ps, appear in various extensions of the Standard Model (SM) that address fundamental questions like the particulate nature of dark matter or baryogenesis. The ANUBIS detector will achieve unprecedented sensitivity to such models compared to existing and approved experiments by instrumenting a large decay volume adjacent to the ATLAS experiment at the high-luminosity LHC with tracking detectors. This paper outlines the proposed detector layouts for ANUBIS, explores their physics potential with a scalar LLP model, and identifies the preferred layout, comparing it to other experiments. The potential background contributions are estimated using a data-driven method, and the topology of potential background events is studied using Monte Carlo simulations. Overall, the ANUBIS detector is expected to probe branching ratios down to O(10−6) for exotic decays of the Higgs boson to scalar long-lived particles with masses of 10, 15, 40, and 60 GeV and proper lifetimes of cτ=2.4, 3.0, 12, and 18 m, respectively. Moreover, for branching ratios of 0.1% of the Higgs boson into long-lived scalars with a mass of 15 GeV, the ANUBIS detector can probe a cτ range between 1.1×10−1  m and 4.0×103  m.

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Phys. Rev. D 114, 092003– Published 6 November, 2026
  • Received 3 December 2025
  • Accepted 20 August 2026
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