Event reconstruction at the LHC, the task of assigning observed physics objects to their true origins, is a central challenge for precision measurements and searches. Many existing machine learning approaches address this problem but rely on a single event topology, restricting their applicability to realistic analyses where multiple signal and background processes with different structures are present. To overcome this, we present TIGER, a novel hierarchical graph network that is fundamentally topology-agnostic. By incorporating only the common underlying structure of sequential two-body decays, our model can reconstruct complex events without process-specific assumptions. This flexible architecture supports multi-task learning, enabling simultaneous event reconstruction and classification. TIGER thus provides a powerful and generalizable tool for physics analysis at the LHC.
@article{arxiv.2510.08162,
title = {TIGER: A Topology-Agnostic, Hierarchical Graph Network for Event Reconstruction},
author = {Nathalie Soybelman and Francesco A. Di Bello and Nilotpal Kakati and Eilam Gross},
journal= {arXiv preprint arXiv:2510.08162},
year = {2026}
}