SET-ANUBIS: a modular pipeline for ANUBIS long-lived particle sensitivity studies

Abstract

The proposed ANUBIS detector has been designed to search for Long-Lived Particle (LLP) signatures, which have become a focus for a variety of experiments within recent years. Due to the variety of possible LLP models and the need for directly comparable sensitivity results highlighting the potential coverage of ANUBIS, the SET-ANUBIS (Simulation, accEptance and sensiTivity studies framework for ANUBIS) framework has been developed. SET-ANUBIS is a flexible open-source Python framework that can perform full sensitivity studies of LLP signatures for the ANUBIS detector, allowing others to directly produce ANUBIS-like limits or even implement other geometries and detectors. It starts from a Universal FeynRules Output model or user-supplied rates; it exposes model parameters and particle content for user modification, and evaluates decay widths, branching ratios and lifetimes. MARTY can also be used to compute matrix elements, decay widths, branching ratios, and cross-sections. Then the framework prepares or runs event generation through Pythia8 or MadGraph, ingests HepMC event records, models the geometry of the ATLAS cavern and ANUBIS tracking stations, and applies a configurable sequence of geometric, kinematic and isolation requirements to select a set of surviving LLP candidates for evaluation. The implementation follows a ports-and-adapters architecture so that the core logic remains separate from external generators, persistent storage and visualisation. A scan-aware SQLite catalogue and content-addressed store preserve cards, metadata and compact selection-ready event bundles while avoiding duplicate artifacts. A pre-release version of the SET-ANUBIS framework has already been used to successfully derive the sensitivity of ANUBIS to three LLP benchmark models involving a Higgs portal and a Heavy Neutral Lepton model.