Design of the Global Reconstruction Logic in the Belle II Level-1 Trigger system
Abstract
The Belle~II experiment is designed to search for physics beyond the Standard Model by investigating rare decays at the SuperKEKB collider. Owing to the significant beam background at high luminosity, the data acquisition system employs a hardware-based Level-1~Trigger to reduce the readout data throughput by selecting collision events of interest in real time. The Belle~II Level-1~Trigger system utilizes FPGAs to reconstruct various detector observables from the raw data for trigger decision-making. The Global Reconstruction Logic receives these processed observables from four sub-trigger systems and provides a global summary for the final trigger decision. Its logic encompasses charged particle tracking, matching between sub-triggers, and the identification of special event topologies associated with low-multiplicity decays. This article discusses the hardware devices, FPGA firmware, integration with peripheral systems, and the design and performance of the trigger algorithms implemented within the Global Reconstruction Logic.
Keywords
Cite
@article{arxiv.2503.02192,
title = {Design of the Global Reconstruction Logic in the Belle II Level-1 Trigger system},
author = {Y. -T. Lai and T. Koga and Y. Iwasaki and Y. Ahn and H. Bae and M. Campajola and B. G. Cheon and H. -E. Cho and T. Ferber and I. Haide and G. Heine and C. -L. Hsu and C. Kiesling and C. -H. Kim and J. B. Kim and K. Kim and S. H. Kim and I. S. Lee and M. J. Lee and Y. P. Liao and J. Lin and A. Little and H. K. Moon and H. Nakazawa and M. Neu and S. Nishida and L. Reuter and V. Savinov and T. -A. Sheng and J. -G. Shiu and Y. Sue and K. Unger and Y. Unno and E. Won and Z. Xu},
journal= {arXiv preprint arXiv:2503.02192},
year = {2025}
}
Comments
10 pages, 12 figures