Thu·Mar 13, 2025Thursday·March 13, 2025

1. 01*

   Probing gluon fluctuations in nuclei with the first energy-dependent measurement of incoherent J/$\psi$ photoproduction in ultraperipheral PbPb collisions

   CMS Collaboration

   Incoherent J/$\psi$ photoproduction in heavy ion ultraperipheral collisions (UPCs) provides a sensitive probe of localized, fluctuating gluonic structures within heavy nuclei. This study reports the first measurement of the photon-nucleon center-of-mass energy ($W_{\gamma \mathrm{N}}$) dependence of this process in PbPb UPCs at a nucleon-nucleon center-of-mass energy of 5.02 TeV, using 1.52 nb${}^{-1}$ of data recorded by the CMS experiment. The measurement covers a wide $W_{\gamma \mathrm{N}}$ range of $\approx$ 40-400 GeV, probing gluons carrying a fraction $x$ of nucleon momentum down to an unexplored region of 6.5 $\times$ 10${}^{-5}$. Compared to baseline predictions neglecting nuclear effects, the measured cross sections exhibit significantly greater suppression at lower $x$. Additionally, the ratio of incoherent to coherent photoproduction is found to be constant across the probed $W_{\gamma \mathrm{N}}$ and $x$ range, disfavoring the establishment of the black disk limit. This study provides critical insights into the $x$-dependent evolution of fluctuating gluonic structures within nuclei and calls for further advancements in theoretical models incorporating nuclear shadowing and gluon saturation.

   nucl-exhep-exPRL(2025)·10 citations
2. 02*

   Advancing multimessenger approaches in heavy-ion collisions: Insights from electromagnetic probes

   Lipei Du🇺🇸

   Electromagnetic (EM) probes, including photons and dileptons, do not interact strongly after their production in heavy-ion collisions, allowing them to carry undistorted information from their points of origin. This makes them powerful tools for studying early-stage equilibration and the thermodynamic properties of the quark-gluon plasma (QGP). In these proceedings, we highlight recent theoretical advancements in EM probes, focusing on their role in probing early-stage dynamics and extracting medium properties. We also discuss the emerging multimessenger approach, which combines hadronic and electromagnetic probes to achieve a more comprehensive understanding of the QGP.

   ↳ nucl-thhep-phnucl-exEPJ Web Conf.(2025)·3 citations
3. 03*

   JENA Computing Initiative WP2 Report: Software and Heterogeneous Architectures

   Mohammad Al-Turany🇩🇪 · David Chamont🇫🇷 · Davide Costanzo🇬🇧 · Caterina Doglioni🇬🇧 · Håvard Helstrup🇳🇴 · Bruno Khélifi🇫🇷 · Thomas Kuhr🇩🇪 · Paul Laycock🇨🇭 · Adrien Matta🇫🇷 · Eva Santos🇨🇿 · Luis Sarmiento Pico🇸🇪 · Fabien Schüssler🇫🇷 and 5 other authors

   The scientific communities of nuclear, particle, and astroparticle physics are continuing to advance and are facing unprecedented software challenges due to growing data volumes, complex computing needs, and environmental considerations. As new experiments emerge, software and computing needs must be recognised and integrated early in design phases. This document synthesises insights from ECFA, NuPECC and APPEC, representing particle physics, nuclear physics, and astroparticle physics, and presents collaborative strategies for improving software, computing frameworks, infrastructure, and career development within these fields.

   ↳ physics.comp-phastro-ph.HEhep-exnucl-ex0 citations
4. 04*

   Study of Tritium Production and Interactions in LiD

   Serena Fattori · Rino Persiani · Ugo Abundo

   This study focuses on a fuel cell composed of Lithium Deuteride (LiD) in a spherical geometry, in which isotropic monoenergetic neutrons of 0.025 eV (thermal neutrons) are generated at the center. The objective is to investigate the production of Tritium via interactions with Lithium-6. The physics of the process has been modeled and analyzed for thirteen different concentrations of Lithium-6 to determine the most advantageous option among them. Monte Carlo simulations were performed using the GEANT4 toolkit to analyze neutron interactions and tritium production efficiency as a function of Lithium-6 concentration.

   ↳ physics.ins-detnucl-exphysics.comp-ph0 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.