Speaker
Description
CODEX-b (COmpact DEtector for EXotics at LHCb) is a proposed transverse detector dedicated to searches for Beyond the Standard Model (BSM) physics through signatures involving Long-Lived Particles (LLPs) with displaced decays. Located in the LHCb cavern, the detector would consist of a 10 × 10 × 10 m³ array of Resistive Plate Chamber (RPC) triplet units, providing sensitivity to regions of parameter space beyond the reach of existing experiments. As a first step towards the realization of the experiment, the CODEX-β demonstrator, a 2 × 2 × 2 m³ RPC-based detector, was developed to validate the detector concept, characterize the expected background environment, and study the operational integration of such a system within LHCb. The demonstrator was successfully installed and started taking data during the latest 2026 LHC data-taking period.
This contribution presents several software and simulation developments that were essential for the commissioning and operation of CODEX-β. GPU-based reconstruction algorithms for HLT1, together with dedicated HLT2 selections, were implemented to enable efficient operation within the LHCb trigger framework. In parallel, a dedicated fast-simulation and digitization framework was developed for CODEX; it was used to validate and test the selection algorithms and is expected to serve as a benchmark for fast simulation in other transverse subdetectors. Significant progress has also been made towards the implementation of a full CODEX detector description within the LHCb simulation framework, enabling realistic studies of detector performance and physics sensitivity. For data analysis, a new framework named COBRA (COdex-b Analysis and Reconstruction) was developed to provide user-friendly analysis tools and to address common challenges in data conversion between HEP data formats. Altogether, these developments demonstrate the feasibility and integration potential of CODEX-b within LHCb, as well as its prospects for future LLP searches.
| Submitted on behalf of ... | Submitted centrally on behalf of the Collaboration |
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