Speaker
Description
Precise reconstruction of particle decay chains is an essential tool for a wide range of analyses in particle physics experiments, particularly those focused on flavour dynamics and CP violation. We present a novel decay tree reconstruction framework designed to handle complex topologies with deeply constrained particle decays, trajectory extrapolations over long distances inside regions with intense and inhomogeneous magnetic fields, and limited momentum resolution. Implemented in C++, the framework is modular, extensible, and optimised for both configurability and performance. It has been integrated into the LHCb software environment with the primary purpose of reconstructing decay chains featuring very displaced vertices located between 2.5 and 8 metres from the LHC primary proton-proton interaction point, but it is flexible enough to handle any type of decay chain. While developed with LHCb in mind, it is suitable for any experiment with a forward geometry. We benchmark its performance using simulated data, demonstrating large improvements in reconstruction efficiency, invariant mass resolution, and vertex position resolution compared to currently existing tools. This framework paves additional possibilities for precision measurements and searches in present and future accelerator experiments.