The physics programme of the LHCb experiment at the Large Hadron Collider requires an efficient and precise reconstruction of the particle collision vertices. The LHCb Upgrade detector relies on a fully software-based trigger with an online reconstruction rate of 30 MHz, necessitating fast vertex finding algorithms. This paper describes a new approach to vertex reconstruction developed for this purpose. The algorithm is based on cluster finding within a histogram of the particle trajectory projections along the beamline and on an adaptive vertex fit. Its implementations and optimisations on x86 and GPU architectures and its performance on simulated samples are also discussed.
@article{arxiv.2412.14966,
title = {A parallel algorithm for fast reconstruction of primary vertices on heterogeneous architectures},
author = {Agnieszka Dziurda and Maciej Giza and Vladimir V. Gligorov and Wouter Hulsbergen and Bogdan Kutsenko and Saverio Mariani and Niklas Nolte and Florian Reiss and Patrick Spradlin and Dorothea vom Bruch and Tomasz Wojton},
journal= {arXiv preprint arXiv:2412.14966},
year = {2025}
}