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IPPOG Collaboration Forum and Author Lists, 2025
No full texthe International Particle Physics Outreach Group is a network of scientists, science educators and communication specialists created in 1997 to demonstrate the need and importance of outreach in science in general and High Energy Particle Physics in particular. Collaboration members are grouped into an informal discussion body called the IPPOG forum, and are offered the possibility to become IPPOG authors. The present lists will be updated once per year, to reflect the collaboration evolution
Luminosity Determination by ALICE during LHC Run 3
No full textLuminosity is a crucial component for measuring the cross-section of physical processes. The ALICE collaboration uses dedicated calibration data, the van der Meer (vdM) scans, to normalize luminosity detectors’s count rate to well-known (visible) cross sections. The needed information comes from LHC instrumentation and ALICE detectors. In the LHC Run 2, three trigger detectors (T0—Cherenkov detector, V0—scintillator, and ZDC—zero degree calirimeter) participated in the luminosity analysis of different colliding systems: pp, p–Pb, and Pb–Pb. During the LHC Long Shutdown 2, a new fast interacting trigger (FIT) detector was integrated with the ALICE setup. This paper gives a preliminary overview of FIT’s performance as the new ALICE luminometer and trigger detector. In addition to the latest data collected during the first pp collisions of Run 3, LHC Run 2 luminosity results are shown and discussed
Irradiation Study of ATLAS ITk Strip Sensors, ATLAS18, with 80MeV Protons
No full textThe ATLAS experiment is planning a complete replacement of its inner detector(ID) with a new all-silicon inner tracker(ITk) for the HL-LHC. To enhance the Quality Assurance (QA) program for confirming the key properties of the sensors, the strip sensor community is considering to include China Spallation Neutron Source (CSNS) as a proton irradiation site and Institute of High Energy Physics (IHEP) as a QA test site. A total of 18 ATLAS ITk strip sensors for the irradiation study were irradiated with protons at CSNS, and measured at IHEP, including IV (leakage current-voltage), CV (capacitance-voltage) and CCE (charge collection efficiency) measurements. The upgraded irradiation setup at CSNS and measurement setup at IHEP are shown in this work Irradiated samples were exchanged between IHEP, Ljubljana and Birmingham to cross-check CCE measurements
Commissioning and exploitation of the MareNostrum5 cluster at the Barcelona Supercomputing Center for CMS computing
No full textThe MareNostrum 5 (MN5) is the newly deployed pre-exascale EuroHPC supercomputer hosted at the Barcelona Supercomputing Center (BSC) in Spain. Its 750,000-core general-purpose CPU cluster offers new opportunities for CMS data processing and simulation but also presents integration challenges within the CMS distributed computing system, particularly due to network segregation for compute nodes. To address these constraints, innovative solutions previously implemented for its predecessor, MN4, have been redeployed, alongside new functionalities to support data-intensive workflows. The system's expanded shared disk storage and enhanced wide-area network connectivity facilitate efficient staging of input datasets, leveraging MN5's substantial CPU capacity. This contribution provides an overview of the commissioning efforts and the subsequent exploitation of MN5 for CMS
Advanced monitoring capabilities of the CMS Experiment for LHC Run3 and beyond
No full textThe CMS computing infrastructure spread globally over 150 WLCG sites forms a intricate ecosystem of computing resources, software and services. In 2024, the production computing cores breached half a million mark and storage capacity is at 250 PetaBytes on disk and 1.20 ExaBytes on Tape. To monitor these resources in real time, CMS working closely with CERN IT has developed a multifaceted monitoring system providing real time insights using about 100 production dashboards.In preparation of Run3, the CMS monitoring infrastructure underwent significant evolution to broaden the scope of monitored applications and services while enhancing sustainability and ease of operation. Leveraging open-source solutions, provided either by the CERN IT department or managed internally, monitoring applications have transitioned from bespoke solutions to standardized data flow and visualization services. Notably, monitoring applications for distributed workload management and data handling have migrated to utilize technologies like OpenSearch, VictoriaMetrics, InfluxDB, and HDFS, with access facilitated through programmatic APIs, Apache Spark, or Sqoop jobs, and visualization primarily via Grafana. The majority of CMS monitoring applications are now deployed on Kubernetes clusters based microservices architecture. This contribution unveils the comprehensive stack of CMS monitoring services, showcasing how the integration of common technologies enables versatile monitoring applications and addresses the computation demands of LHC Run 3. Additionally, it explores the incorporation of analytics into the monitoring framework, demonstrating how these insights contribute to the operational efficiency and scientific output of the CMS experiment
Schematic map showing a possible location for the Future Circular Collider
No full textArtistic schematic map showing a possible location for the 90.7 km Future Circular Collider, 180 to 400 m depths for access shafts, 8 surface sites (7 in France, 1 in Switzerland
ATLAS Event Display: Longitudinally polarized W bosons
No full textVisualization of a candidate event in the signal region dominated by events featuring at least one longitudinally polarized W boson. The red tracks represent the two reconstructed muons, while the yellow cones illustrate the forward jets with a dijet invariant mass of about 3 TeV. The dotted white line indicates the transverse missing energy associated with the two neutrinos in the final state
South Africa’s Contribution to the Upgrade of the ATLAS TileCal low voltage power supply for the HL-LHC
No full textThe start of the operation of the High Luminosity LHC (HL-LHC) is planned for the year 2030. The associated increase in luminosity provides an opportunity for further scientific discoveries as while also introducing many technical challenges for the systems of ATLAS. The HL-LHC environment has necessitated the Phase-II upgrade of the ATLAS hadronic Tile-Calorimeter (TileCal) which will ensure its peak performance in the coming decades. The upgrade will take place during the third long shutdown of the LHC. It will encompass the replacement of both on- and off-detector electronics, the implementation of new on-detector mechanics as well as the replacement of Photo-multiplier tubes located in the most exposed regions of the detector. The on-detector electronics of the TileCal are powered by 256 adjacent Low-Voltage Power Supplies (LVPS) which themselves contain eight transformer-coupled buck converters known as Bricks. These Bricks function to step-down power received from off-detector bulk power supplies to that required by the front-end electronics. The South African cluster, headed by the University of the Witwatersrand, is responsible for the research and development, production, quality assurance testing and integration of half of the required Bricks for the Phase-II Upgrade. This presentation will provide an overview of the South African cluster's contributions to the development and production of the LVPS Bricks for the ATLAS Tile-Calorimeter Phase-II Upgrade. It will highlight the current project milestones, including research, development, and quality assurance achievements, and conclude with a forward-looking perspective on the remaining activities critical for ensuring the success of the project