The High-Luminosity Large Hadron Collider (HL-LHC) will deliver a five- to seven-fold increase in instantaneous luminosity relative to the original LHC design, and approximately a three-fold increase compared to Run-3 operation, significantly increasing detector readout volumes and placing substantially higher demands on the trigger and data-acquisition systems. To meet these challenges, the ATLAS Event Filter Tracking group is evaluating heterogeneous computing platforms to reduce the size, cost, and power consumption of the event-processing farm. Options where key algorithms of the processing are offloaded to either FPGA or GPU accelerator cards are compared directly to a traditional CPU-only farm. This contribution presents an FPGA-based implementation of the pattern-recognition stage in the tracking pipeline, developed using High-Level Synthesis and integrated within the ATLAS Athena software framework using the OpenCL cross-platform programming model. We describe the architecture, firmware design choices, and workflow for hardware–software co-execution. Performance studies compare physics efficiency and throughput of FPGA implementation against other technologies, demonstrating the potential of FPGA acceleration for the HL-LHC Event Filter. Pattern Recognition algorithm in FPGA Pipeline The Event Filter Tracking group is evaluating FPGA technology as a platform for implementing data-preparation and tracking algorithms for the ATLAS experiment. In this workflow, data from the ATLAS Inner Tracker (ITk) subsystem is transferred into the Athena software framework, which launches the FPGA-based processing pipeline via OpenCL cross-platform APIs, thus transferring approximately 50% of the tracking algorithms onto the FPGA.

We report on the first observation of the semitauonic $b$-baryon decay $\Lambda_b^0 \to \Lambda_c^+ \tau^- \bar{\nu}_\tau$~\cite{ref1,ref2} using $3\,\mathrm{fb}^{-1}$ of LHCb Run~1 data. This decay provides a stringent test of Lepton Flavour Universality (LFU) and offers complementary sensitivity to potential New Physics beyond mesonic anomalies such as $R(D^{*})$. The analysis reconstructs the $\tau$ lepton in its three-prong hadronic decay and employs a novel ``inversion cut'' to suppress prompt backgrounds. The signal is extracted via a three-dimensional template fit to $q^2$, $\tau$ lifetime, and BDT output, achieving a significance of $6.1\sigma$. The LFU ratio is measured to be $R(\Lambda_c^+) = 0.242 \pm 0.026\,(\mathrm{stat}) \pm 0.040\,(\mathrm{syst}) \pm 0.059\,(\mathrm{ext})$, consistent with the Standard Model within $1.1\sigma$. This result provides an important baryonic test of LFU and can be interpreted in the context of theoretical correlations with mesonic observables. Prospects for improved precision using the full Run~1+2+3 datasets are also discussed.

Light hadrons constitute the bulk of particle production in heavy-ion collisions. Its properties, such as the production cross-sections of different hadron species or their average transverse momentum, are sensitive to both collective phenomena and the initial state of heavy-ion collisions. Bulk physics measurements in small collision systems can reveal the interplay between initial- and final-state effects in heavy-ion collisions, and can provide new insights into the origins of collective phenomena. The LHCb detector, with its high-resolution tracking system and its hadron ID capabilities, is perfectly suited for these studies in the forward region. In this contribution, new results on bulk measurements in small systems will be presented.

The $\phi$ meson is a unique probe of strange quark dynamics in high-energy nuclear collisions. The $\phi$ meson's mass lies at the threshold between perturbative and nonperturbative QCD. Consequently, $\phi$ production provides sensitivity to both regimes. In heavy-ion collisions, $\phi$-meson production is senstive to strange-quark coalescence in quark-gluon plasma. The $\phi$ meson's net-zero strangeness means that $\phi$ production measurements can help disentangle the physical mechanisms behind strangeness enhancement in high-energy hadron and nucleaer collisions. The LHCb detector's hadron identification capabilities allow for precise studies of $\phi$ meson production in nuclear collisions. In addition, the SMOG system allows LHCb to study production in fixed-target collisions. New measurements of $\phi$ production in both collider and fixed-target configurations will be presented.

Ultra-peripheral collisions provide a unique environment to study pomeron- and photon-induced reactions with heavy nuclei. These interactions can produce a wide range of final state particles, from light vector mesons to heavy quarkonia, and probe potentially exotic phenomena. With a fast and flexible DAQ, full particle ID, and the ability to reconstruct very low pt particles, LHCb is uniquely well suited to study final states with leptons, hadrons or photons. Also, using the HeRSCheL detector, the far forward event activity can be detected and used to tag events with nuclear break-up. In this contribution, we will present recent LHCb results from ultra-peripheral heavy ion collisions and discuss how these impact our understanding new exotic phenomena, the partonic structure of nuclei and hadronization in small systems.

At CERN, we probe the fundamental structure of particles that make up everything around us. We do so using the world’s largest and most complex scientific instruments. This visual exhibition focuses mainly on photos, offers visitors the opportunity to explore CERN through 18 posters.

At CERN, we probe the fundamental structure of particles that make up everything around us. We do so using the world’s largest and most complex scientific instruments. This visual exhibition focuses mainly on photos, offers visitors the opportunity to explore CERN through 18 posters.

Représentation des infrastructures souterraines du FCC, conçue pour la vulgarisation technique et scientifique auprès du grand public (non à l’échelle).

The Faces of CERN: People Advancing Science. At the heart of CERN, curiosity guides scientific research and brings together a myriad of unexpectedly diverse professions: physicists, engineers, computer scientists, but also communications specialists, lawyers, accountants, administrators, and security experts, to name just a few. Together, they push the boundaries of our knowledge by operating complex machines and data systems and conducting cutting-edge research. CERN thus acts as a true talent accelerator, preparing the science of tomorrow.Les visages du CERN : les personnes qui font avancer la science. Au cœur du CERN, la curiosité guide la recherche scientifique et réunit des métiers d’une richesse insoupçonnée : physiciens, ingénieurs, informaticiens, mais aussi communicants, juristes, comptables, administrateurs ou spécialistes de la sécurité, pour ne citer que quelques exemples. Ensemble, ils repoussent les limites de nos connaissances en faisant fonctionner des machines et des systèmes de données complexes et en menant des recherches de pointe. Le CERN agit ainsi comme un véritable accélérateur de talents, préparant la science de demain.

The Faces of CERN: People Advancing Science. Immerse yourself in this network, where each thread tells a story of curious collaboration and showcases your talents.Les visages du CERN : les personnes qui font avancer la science. Plonger dans cet univers, où chaque fil raconte une histoire de curiosité et de collaboration, et met en scène vos talents.