arXiv subjects

C. -J. Naïm

Publications and source records attributed to C. -J. Naïm.

3 recordsLinked to original sources

arXiv2026

Hybrid Machine-Learning Particle Identification for the ePIC Proximity-Focusing RICH

We present a machine-learning-based particle-identification study for the proximity-focusing Ring Imaging Cherenkov (pfRICH) detector of the ePIC experiment at the Electron-Ion Collider. Operating in the backward region ($-3.5 \lesssim η\lesssim -1.5$), the pfRICH is designed to achieve at least $3σ$ separation among pions, kaons, and protons up to $7,\mathrm{GeV}/c$ for Semi-Inclusive Deep Inelastic Scattering measurements. Using a standalone Geant4 simulation of the pfRICH, we develop a hybrid machine-learning approach that combines convolutional neural-network-based feature extraction with gradient-boosted decision-tree classifiers. This method significantly enhances Cherenkov-ring pattern recognition and improves particle-separation performance, demonstrating the effectiveness of hybrid machine-learning techniques for next-generation Cherenkov detectors at the EIC.

physics.ins-det↗

arXiv2026

Physics Opportunities with a Fixed-Target Program at the Electron-Ion Collider

A fixed-target program at the Electron-Ion Collider (EIC) would broaden the facility's scientific reach by providing key measurements for studies of cold nuclear matter (CNM), the QCD phase diagram, and nuclear reactions relevant for space radiation. Constraining CNM effects is essential for interpreting observables in proton-nucleus ($p+A$) and nucleus-nucleus ($A+A$) collisions, yet these effects are poorly understood at low center-of-mass energies. In particular, the range $\sqrt{s}\approx10$--20 GeV, where several CNM effects may compete at similar scales, has not been explored with high statistical precision. Mapping the QCD phase diagram similarly requires high-statistics $A+A$ data with broad rapidity and transverse-momentum coverage to probe the onset of deconfinement and the possible location of the QCD critical point (CP). Currently, such data are limited at 4.5 GeV $< \sqrt{s_{NN}} < 7.7$ GeV A fixed-target program at the EIC would fill these gaps, providing CNM baselines and complementary data for QCD CP studies. By delivering high luminosity and systematic measurements across a broad range of nuclear targets, the program would link $p+A$ and $A+A$ systems at the same center-of-mass energies, enabling a unified, quantitative description of cold QCD matter and clarifying the interpretation of QGP signatures in $A+A$ collisions at low energies where comparable $p+A$ data are lacking. Finally, the program would offer a unique opportunity to measure nuclear cross sections critical for improving cosmic-ray models, including studies of space-radiation protection for both autonomous spacecraft and long-duration human spaceflight.

nucl-ex↗

arXiv2025

Nuclear Cold QCD: Review and Future Strategy

This review examines data from hadron-nucleus collisions, primarily focusing on hard processes like Drell-Yan, heavy flavor and quarkonium production. It highlights observed modifications of particle yields as functions of momentum and rapidity, aiming to clarify the underlying QCD effects in cold nuclear matter (CNM). The paper outlines strategies for future experiments, including the Electron-Ion Collider (EIC), to distinguish between these effects. Key questions address the universality of suppression mechanisms and the role of non-perturbative physics, providing a road map for upcoming nuclear data.

hep-ph↗