arXiv subjects

Santiago Folgueras

Publications and source records attributed to Santiago Folgueras.

9 recordsLinked to original sources

arXiv2026

FPGA-based muon shower identification and graph neural network tracking algorithms for HL-LHC triggers

This work presents two hardware-accelerated strategies for the upgrade of the CMS Level-1 Trigger (L1T) to target efficiency losses due to highly energetic radiating muons and unconventional physics signatures, such as Long-Lived Particles (LLPs). Operating directly on low-level detector hits, the first strategy implements a dedicated muon shower identification algorithm in the CMS barrel region that monitors hit multiplicities in the Drift Tube chambers to generate Shower Primitives. Executing with sub-bunch-crossing latency and ultra-low resource consumption, this algorithm successfully tags showered muons and provides essential context for downstream track finders. The second approach targets the barrel-endcap transition (overlap) region by evaluating Graph Neural Networks to reconstruct displaced muon tracks. Following a divided methodology that first isolates hardware feasibility from evolving physics refinements, an initial proxy model based on a GraphSAGE architecture is evaluated to validate its viability on FPGAs within strict latency limits. This implementation utilizes an INT8-PO2 quantization technique coupled with a data-driven bit-width optimization. By replacing DSP-heavy fixed-point multiplications with fast compile-time arithmetic bit-shifts and allocating the minimum required bits per signal, this hardware-software co-design reduces DSP utilization to $20\%$ and achieves a deterministic inference latency of just $19$ clock cycles. Together, these developments pave the way for triggering on non-standard muon signatures, such as those from LLP decays, at L1T.

hep-ex↗

arXiv2026

Integer Quantization of Graph Neural Networks for Real-Time FPGA Track Finding

Real-time track finding for displaced-muon signatures in the CMS Level-1 trigger must operate under strict fixed-latency constraints of 12.5 $μ$s while processing high-throughput detector data. Because muon hits map naturally onto sparse, irregular graphs, graph neural networks (GNNs) are attractive candidates; however, mapping message-passing models to field-programmable gate arrays (FPGAs) requires careful co-design of numerical precision, microarchitecture, and high-level synthesis (HLS) implementation. This work presents a reproducible, bit-exact workflow bridging GNN design and FPGA prototyping for fixed-latency inference. The methodology is demonstrated by implementing a two-layer GraphSAGE network onto an XCVU13P FPGA, using the Cora citation network as a fixed-size benchmark for firmware evaluation that decouples deployment feasibility from the physics task. Starting from a 32-bit floating-point reference that exceeds the available FPGA resource budget, we derive an integer-only datapath through post-training quantization (INT8 weights and activations, INT32 biases), a power-of-two scale approximation that replaces rescaling multipliers with arithmetic shifts, and data-driven bit-width narrowing. Every stage is validated bit-exactly against a Python integer emulator in Vitis HLS C-simulation. The optimized INT8 power-of-two design achieves an inference latency of 19 clock cycles (52.8 ns at the nominal 360 MHz clock) at 20\% DSP, 6\% FF, and 27\% LUT utilization, with 75.0$\pm$1.1\% accuracy compared to the 78.0$\pm$0.8\% for FP32. Accuracy is reported as the average across multiple training seeds. The resulting workflow establishes a concrete, transferable path toward fixed-latency GNN-based track reconstruction in the CMS Level-1 trigger.

hep-ex↗

arXiv2026

Multiboson and VBS measurements in ATLAS and CMS

A review of recent multiboson and vector boson scattering (VBS) measurements from the ATLAS and CMS Collaborations at the LHC is presented. Results are reported from precision diboson cross-section measurements, novel CP-sensitive and polarisation observables in $Wγ$ production, VBS observations in semileptonic and fully leptonic final states including the first measurements at $\sqrt{s}$ = 13.6 TeV, and observations of triboson processes. These results constitute a comprehensive test of the electroweak gauge sector of the Standard Model, and provide stringent constraints on anomalous gauge couplings in the effective field theory framework.

hep-ex↗

arXiv2026

On the Codesign of Scientific Experiments and Industrial Systems

The optimization of large experiments in fundamental science, such as detectors for subnuclear physics at particle colliders, shares with the optimization of complex systems for industrial or societal applications the common issue of addressing the inter-relation between parameters describing the hardware used in data production and parameters used to analyse those data. While in many cases this coupling can be ignored -- when the problem can be successfully factored into simpler sub-tasks and the latter addressed serially -- there are situations in which that approach fails to converge to the absolute maximum of expected performance, as it results in a mis-alignment of the optimized hardware and software solutions. In this work we consider a few use cases of interest in fundamental science collected primarily from particle physics and related areas, and a pot-pourri of industrial and societal applications where the matter is similarly of relevance. We discuss the emergence of strong hardware-software coupling in some of those systems, as well as co-design procedures that may be deployed to identify the global maximum of their relevant utility functions. We observe how numerous opportunities exist to advance methods and tools for hardware-software co-design optimization, bridging fundamental science and industry through application- and challenge-driven projects, and shaping the future of scientific experiments and industrial systems.

physics.ins-det↗

arXiv2025

Using AI on FPGAs for the CMS Overlap Muon Track Finder for the HL-LHC

Operating the CMS Level-1 trigger under the intense conditions of the High-Luminosity Large Hadron Collider -- with approximately 63~Tb/s of input and a fixed 12.5~$μ$s latency -- poses a demanding real-time reconstruction challenge. The CMS muon system is organized into three regions: a barrel, an endcap, and the intermediate barrel-endcap ``overlap'' region. In this overlap transition, the Overlap Muon Track Finder can be suboptimal for displaced-muon and long-lived-particle signatures. We present a first approach to a graph neural network tailored to these constraints, using GraphSAGE layers and a compact multi-layer perceptron to regress the inverse transverse momentum of muons. A PyTorch to C++ and high-level synthesis flow demonstrates feasibility, with initial results showing good agreement with simulation. Although a fully parallel implementation would exceed available field-programmable gate array resources, quantization, pruning, and multiplier reuse point the way toward a practical Phase-2 deployment.

hep-ex↗

arXiv2025

Harnessing Hardware Acceleration in High-Energy Physics through High-Level Synthesis Techniques

At the Large Hadron Collider, the vast amount of data from experiments demands not only sophisticated algorithms but also substantial computational power for efficient processing. This paper introduces hardware acceleration as an essential advancement for high-energy physics data analysis, focusing specifically on the application of High-Level Synthesis (HLS) to bridge the gap between complex software algorithms and their hardware implementation. We will explore how HLS facilitates the direct implementation of software algorithms into hardware platforms such as FPGAs, enhancing processing speeds and enabling real-time data analysis. This will be highlighted through the case study of a track-finding algorithm for muon reconstruction with the CMS experiment, demonstrating HLS's role in translating computational tasks into high-speed, low-latency hardware solutions for particle detection and reconstruction. Key techniques in HLS, including parallel processing, pipelining, and memory optimization, will be discussed, illustrating how they contribute to the efficient acceleration of algorithms in high-energy physics. We will also cover design methodologies and iterative processes in HLS to optimize performance and resource utilization, alongside a brief mention of additional techniques like algorithm approximation and hardware / software co-design. In short, this paper will underscore the potential of hardware acceleration in high-energy physics research, emphasizing HLS as a powerful tool for physicists to enhance computational efficiency and foster groundbreaking discoveries.

hep-ex↗

arXiv2015

Searches for weakly produced SUSY at LHC

A summary of the different searches for weakly produced SUSY by both CMS and ATLAS is presented here. A review on the methodology of these searches, including event selection, background suppression and estimation methods, etc is covered. Other searches at the LHC already probe squarks and gluino masses up to 1.4 TeV, such scenario, may favour electroweak production of charginos and neutralinos, that will produce many-lepton final states accompanied by E$_{\rm T}^{\rm miss}\,$ and very little hadronic activity. Latest searches include Higgs boson in the decay and exploits VBF associated production to probe scenarios with very small mass splittings.

hep-ex↗

arXiv2014

Search for new physics using events with two same-sign isolated leptons in the final state in pp collisions at 8 TeV

A search for new physics is performed based on events with jets and a pair of isolated, same-sign leptons. The results are obtained using a sample of proton-proton collision data collected by the CMS experiment at a centre-of-mass energy of 8 TeV at the LHC, corresponding to an integrated luminosity of 19.5 inverse femtobarns. In order to be sensitive to a wide variety of possible signals beyond the standard model, multiple search regions defined by the missing transverse energy, the hadronic energy, the number of jets and b-quark jets. No excess above the standard model background expectation is observed and constraints are set on a number of models for new physics.

hep-ex↗

arXiv2013

Search for new physics using events with two same-sign isolated leptons in the final state at CMS

We present a search for new physics using events with two same-sign isolated leptons with/out the presence of b-jets in the final state, targetting two very different SUSY scenarios, one dominated by strong production of squarks and gluinos where the 3rd generation squarks are lighter than other squarks and the other dominated by electroweak production neglecting completely any strongly interacting particles. No excees above the standard model background is observed. The results are interpreted in various SUSY models.

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