A real-time demonstrator of track reconstruction with FPGAs at LHCb

Francesco Terzuoli; Wander Baldini; Giovanni Bassi; Andrea Contu; Riccardo Fantechi; Sofia Kotriakhova; Federico Lazzari; Michael Joseph Morello; Giovanni Punzi; Giulia Tuci

arXiv · 2605.02753

A real-time demonstrator of track reconstruction with FPGAs at LHCb

Francesco Terzuoli·Wander Baldini·Giovanni Bassi·Andrea Contu·Riccardo Fantechi·Sofia Kotriakhova·Federico Lazzari·Michael Joseph Morello·Giovanni Punzi·Giulia Tuci

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Abstract

The upgraded LHCb detector has started its Run 3 of data taking in 2022, with a completely overhauled DAQ system, reading out and processing the full detector data at every LHC bunch crossing (30 MHz average rate). At the same time, an intense R&D activity is taking place, with the aim of further improving the real-time data processing performance of LHCb, in view of "Upgrade II", where luminosity will be increased. In this work, we describe the experience gained with a prototype device for a 30 MHz real-time tracking in the LHCb VELO detector, implemented in state-of-art PCIe-hosted FPGA cards interconnected by fast optical links. The system has been processing live LHCb data opportunistically during physics data taking, thanks to a dedicated TestBed facility fed by the experiment monitoring system. We describe, amongst other things, the system used to organise and optimise the high-speed distribution of data to the components, and the synchronisation with the most updated alignment constants to be used in track reconstruction.

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Francesco Terzuoli, Wander Baldini, Giovanni Bassi, Andrea Contu, Riccardo Fantechi, Sofia Kotriakhova, Federico Lazzari, Michael Joseph Morello, Giovanni Punzi, Giulia Tuci. 2026-05-04. A real-time demonstrator of track reconstruction with FPGAs at LHCb. https://arxiv.org/abs/2605.02753

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