arXiv subjects

Jan Eysermans

Publications and source records attributed to Jan Eysermans.

8 recordsLinked to original sources

arXiv2026

Client-side transparent caching for remote ROOT data analysis

High-energy physics analyses often process the same data as physicists refine algorithms and test new ideas. With data increasingly read from remote storage, each iteration is subject to network latency and depends on network bandwidth and shared-storage throughput, which can vary substantially under load. We present uCache (xrd-ucache), a transparent client-side cache implemented as an XRootD client plugin that requires neither server-side deployment nor changes to analysis code. It uses local storage on the analysis machine as a cache layer between the network and memory. The cache stores only the data actually read by an analysis. It can also rebuild cached data into a branch-aligned, recompressed form, eliminating most of the input/output and decompression costs of subsequent passes. We benchmark the cache using the Analysis Grand Challenge top quark pair analysis on public CMS Open Data compressed with zlib and LZMA. Filling the cache adds essentially no overhead compared with a direct read. Subsequent passes are 1.6-8.8 times faster from the byte cache and 2.1-15.7 times faster from the recompressed cache. For a typical analysis, a 1 TB cache suffices for datasets of 10-20 TB. The largest improvements occur when the remote data source is heavily loaded or geographically distant.

cs.DC↗

arXiv2026

Toward a Measurement of the Higgs Boson Mass with Natural-Width Precision at FCC-ee

Higgs boson mass measurements with sub-10 MeV precision enable sub-percent determinations of Higgs boson couplings and prevent the Higgs boson mass from becoming a limiting input to electroweak fits. Probing the electron Yukawa coupling through resonant Higgs boson production requires a precision comparable to the Higgs boson natural width of approximately 4 MeV. Using the leptonic ZH recoil channels, we show that FCC-ee can reach a Higgs boson mass precision of 4 MeV, including statistical and systematic uncertainties, thereby enabling this unique measurement. We identify the detector and accelerator performance required to reach this precision.

hep-ex↗

arXiv2026

D$e^+e^-$ffusion: Capturing the Beam-Beam Physics of $e^+e^-$ Collisions with Diffusion Models

Beam-induced backgrounds at high-luminosity $e^+e^-$ colliders, such as the FCC-ee, are dominated by incoherent pair creation (IPC), and require computationally expensive simulations with dedicated Monte Carlo (MC) event generators. Reliable detector and machine-detector interface studies necessitate event samples that are several orders of magnitude larger than what is practically attainable with existing MC. To alleviate this bottleneck, we present D$e^+e^-$ffusion, a denoising diffusion probabilistic model that operates as a permutation-equivariant, set-valued surrogate for fast IPC simulation. Trained on a small GuineaPig++ sample, D$e^+e^-$ffusion faithfully reproduces the marginal and joint kinematic, angular, and positional distributions of all three IPC production processes. In addition, we assess the fidelity at the detector level by propagating both Geant4 and D$e^+e^-$ffusion events through a Geant4 simulation of the CLD vertex detector and by training a transformer-based two-sample classifier; the classifier achieves an area under the ROC curve of $0.553 \pm 0.016$. The trained model generates events nearly four orders of magnitude faster than Geant4, paving the way for a fast-simulation surrogate for FCC-ee design studies.

hep-ph↗

arXiv2026

Machine Learning on Heterogeneous, Edge, and Quantum Hardware for Particle Physics (ML-HEQUPP)

The next generation of particle physics experiments will face a new era of challenges in data acquisition, due to unprecedented data rates and volumes along with extreme environments and operational constraints. Harnessing this data for scientific discovery demands real-time inference and decision-making, intelligent data reduction, and efficient processing architectures beyond current capabilities. Crucial to the success of this experimental paradigm are several emerging technologies, such as artificial intelligence and machine learning (AI/ML), silicon microelectronics, and the advent of quantum algorithms and processing. Their intersection includes areas of research such as low-power and low-latency devices for edge computing, heterogeneous accelerator systems, reconfigurable hardware, novel codesign and synthesis strategies, readout for cryogenic or high-radiation environments, and analog computing. This white paper presents a community-driven vision to identify and prioritize research and development opportunities in hardware-based ML systems and corresponding physics applications, contributing towards a successful transition to the new data frontier of fundamental science.

physics.ins-det↗

arXiv2025

Model-independent ZH production cross section at FCC-ee

This paper presents prospects for measuring the model-independent $ZH$ production cross section at the FCC-ee using the recoil-mass method at center-of-mass energies of 240 GeV and 365 GeV. Analyses are carried out in the muon, electron, and hadronic decay modes of the associated $Z$ boson. The event selections rely primarily on the kinematics of the reconstructed $Z$ decay products, ensuring maximal independence from specific Higgs boson decay modes, while multivariate techniques are employed to further enhance sensitivity. The statistical interpretation of the leptonic and hadronic final states at 240 GeV, with an integrated luminosity of 10.8 ab$^{-1}$, yields relative precisions of 0.52% for the combined leptonic channels and 0.38% for the hadronic channel. Their full statistical combination leads to total uncertainties of 0.31% at 240 GeV and 0.52% at 365 GeV, the latter assuming an integrated luminosity of 3.12 ab$^{-1}$. Dedicated statistical tests demonstrate model independence at the level of the obtained precision. This study presents the first consistent and combined analysis of the leptonic and hadronic final states for a model-independent $ZH$ cross-section measurement at a future lepton collider, using a unified workflow and covering both $\sqrt{s}=240$ and 365 GeV. It provides the most precise expected measurement of the $ZH$ production cross section at future lepton colliders, with the degree of model independence demonstrated within the achieved statistical precision.

hep-ex↗

arXiv2025

Precision Measurements of Higgs Hadronic Decay Modes at the FCC-ee

The expected precision at the FCC-ee on the product $\sigma\times\mathcal{B}(H\rightarrow b\bar{b}, c\bar{c},s\bar{s},gg)$ of Higgs boson production cross sections times branching ratios of hadronic decays is presented. This study provides the first comprehensive determination of all major hadronic Higgs decay modes in a combined fit at future $e^+ e^-$ colliders, using both Higgs-strahlung ($ZH$) and Vector boson fusion ($\nu\bar{\nu} H$) production processes, with a full treatment of interference effects in the $\nu\bar{\nu} jj$ final state. It assumes four identical IDEA detectors collecting $e^+e^-$ collisions at $\sqrt{s}=240$ and $365\,$GeV. The combination of all channels across both energies, with full covariance between production and decay modes, yields a production cross-section times branching-ratio precision at the percent to per-mil level for the dominant hadronic final states ($b\bar{b}, c\bar{c},gg$). These results provide a comprehensive input to the determination of Higgs coupling projections at the FCC-ee, and they establish for the first time sensitivity to the rare decay $H\rightarrow s\bar{s}$, demonstrating that FCC-ee has the potential to provide evidence of the strange-quark Yukawa coupling.

hep-ex↗

arXiv2025

SubMIT: A Physics Analysis Facility at MIT

The recently completed SubMIT platform is a small set of servers that provide interactive access to substantial data samples at high speeds, enabling sophisticated data analyses with very fast turnaround times. Additionally, it seamlessly integrates massive processing resources for large-scale tasks by connecting to a set of powerful batch processing systems. It serves as an ideal prototype for an Analysis Facility tailored to meet the demanding data and computational requirements anticipated during the High-Luminosity phase of the Large Hadron Collider. The key features that make this facility so powerful include highly optimized data access with a minimum of 100Gbps networking per server, a large managed NVMe storage system, and a substantial spinning-disk Ceph file system. The platform integrates a diverse set of high multicore CPU machines for tasks benefiting from the multithreading and GPU resources for example for neural network training. SubMIT also provides and supports a flexible environment for users to manage their own software needs for example by using containers. This article describes the facility, its users, and a few complementary, generic and real-life analyses that are used to benchmark its various capabilities.

cs.DC↗

arXiv2021

A special Higgs challenge: Measuring the mass and production cross section with ultimate precision at FCC-ee

The FCC-ee offers powerful opportunities to determine the Higgs boson parameters, exploiting over $10^6$ ${\rm e^+e^- \to ZH}$ events and almost $10^5$ ${\rm WW \to H}$ events at centre-of-mass energies around 240 and 365 GeV. This essay spotlights the important measurements of the ZH production cross section and of the Higgs boson mass. The measurement of the total ZH cross section is an essential input to the absolute determination of the HZZ coupling -- a "standard candle" that can be used by all other measurements, including those made at hadron colliders -- at the per-mil level. A combination of the measured cross sections at the two different centre-of-mass energies further provides the first evidence for the trilinear Higgs self-coupling, and possibly its first observation if the cross-section measurement can be made accurate enough. The determination of the Higgs boson mass with a precision significantly better than the Higgs boson width (4.1 MeV in the Standard Model) is a prerequisite to either constrain or measure the electron Yukawa coupling via direct ${\rm e^+e^- \to H}$ production at $\sqrt{s} = 125$ GeV. Approaching the statistical limit of 0.1% and $\mathcal{O}(1)$ MeV on the ZH cross section and the Higgs boson mass, respectively, sets highly demanding requirements on accelerator operation (ZH threshold scan, centre-of-mass energy measurement), detector design (lepton momentum resolution, hadronic final state reconstruction performance), theoretical calculations, and analysis techniques (efficiency and purity optimization with modern tools, constrained kinematic fits, control of systematic uncertainties). These challenges are examined in turn in this essay.

hep-ex↗