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New techniques for reconstructing, calibrating and identifying hadronic objects with ATLAS
No full textExperimental uncertainties related to hadronic object reconstruction can limit the precision of physics analyses at the LHC, and so improvements in performance have the potential to broadly increase the impact of results. Recent refinements to reconstruction, calibration and identification procedures for ATLAS jets and missing transverse momentum result in reduced uncertainties, improved pile-up stability and other performance gains. In this contribution, highlights of these developments are presented
CERN PGDay 2025
No full textCERN is known for producing, processing, and storing vast amounts of data, most of which consists of physics-related information — snapshots of particle collisions recorded by detectors in experiments. Large Detector Control Systems at CERN enable the controlled operation of complex research equipment and generate "conditions" data. This data describes the time evolution of parameters such as voltages, pressures, and temperatures, which are essential for physics data analysis and ensuring reproducibility.
These control systems include over 800 mission-critical SCADA systems built on SIMATIC WinCC Open Architecture software, developed by ETM (Siemens). Together, they produce hundreds of gigabytes of time-series data daily. Storing and querying this data efficiently is the responsibility of the NextGen Archiver module of WinCC OA, a solution developed collaboratively by CERN and Siemens through the CERN openlab project. The ever-growing data volumes and throughput, combined with the need for fast, responsive user interfaces for data visualization, have posed significant challenges for the project.
In this presentation, we will share the lessons learned during the development of the NextGen Archiver. The NextGen Archiver supports multiple database technologies through pluggable backends, offering PostgreSQL and TimescaleDB as alternatives to Oracle Database, which has been used for WinCC OA archiving for over 15 years.
We will walk you through the processes and tools used to evaluate the performance and scalability of various database technologies and schemas considered during the project. Additionally, we will examine the impact of TimescaleDB features, such as compression and continuous aggregates, on improving query performance and reducing storage requirements
Search for charge-parity violation in semileptonically tagged decays
No full textAn analysis of the flavour oscillations of the charmed neutral meson is presented. The ratio of and decay rates is measured as a function of the decay time of the meson and compared with the charge-conjugated system to search for charge-parity violation. The meson flavour at production is double-tagged by the charges of the muon and pion in the preceding and decays, respectively. These decays are selected from proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of and corresponding to an integrated luminosity of . The flavour oscillation parameters, relating to the differences in mass and width of the mass eigenstates, are found to be and . No evidence for charge-parity violation is seen either in the flavour oscillations or in the decay, where the direct charge-parity asymmetry is measured to be .An analysis of the flavour oscillations of the charmed neutral meson is presented. The ratio of D → Kπ and D → Kπ decay rates is measured as a function of the decay time of the D meson and compared with the charge-conjugated system to search for charge-parity violation. The meson flavour at production is double-tagged by the charges of the muon and pion in the preceding and D(2010) → Dπ decays, respectively. These decays are selected from proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 5.4 fb. The flavour oscillation parameters, relating to the differences in mass and width of the mass eigenstates, are found to be y′ = (5.8 ± 1.6) × 10 and (x′) = (0.0 ± 1.2) × 10. No evidence for charge-parity violation is seen either in the flavour oscillations or in the decay, where the direct charge-parity asymmetry is measured to be A = (2.3 ± 1.7) %.[graphic not available: see fulltext]An analysis of the flavour oscillations of the charmed neutral meson is presented. The ratio of and decay rates is measured as a function of the decay time of the meson and compared with the charge-conjugated system to search for charge-parity violation. The meson flavour at production is double-tagged by the charges of the muon and pion in the preceding and decays, respectively. These decays are selected from proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of and corresponding to an integrated luminosity of . The flavour oscillation parameters, relating to the differences in mass and width of the mass eigenstates, are found to be and . No evidence for charge-parity violation is seen either in the flavour oscillations or in the decay, where the direct charge-parity asymmetry is measured to be
Recent Updates to the Popular ATLAS Virtual Visit Programme
No full textVirtual Visits have been an integral component of the ATLAS Education and Outreach programme since their inception in 2010. Over the years, collaboration members have hosted visits for tens of thousands of visitors located all over the globe. In 2024, alone there have already been 59 visits through the month of May. Visitors in classrooms, festivals, events or even at home have a unique opportunity to engage with scientists located either underground in the ATLAS experimental cavern or in front of the control room, to learn about the goals and achievements of the collaboration. As part of the renovation of the ATLAS Visitor Centre at LHC Point 1, a new installation was constructed to facilitate Virtual Visits during the running of LHC. We present the overall programme, the new installation and discuss recent initiatives to expand our reach, including Open Visits on Zoom, Facebook, YouTube and TikTok Live
Charting Quantum Frontiers: Unveiling Nature's Essence through First-Principles Simulation of Fundamental Forces
No full textThe Standard Model of particle physics grapples with notable gaps, failing to elucidate critical aspects of our universe, such as the existence of dark matter and the intriguing baryon-antibaryon asymmetry. Unraveling the mysteries requires scrutinizing experimental data against Standard Model predictions, a task hindered by the intricate nonperturbative nature of the strong interaction. Classical simulation methods, like Euclidean lattice QCD, prove inadequate for many pertinent processes. In this context, quantum computing emerges as a transformative force, holding the promise to revolutionize the simulation of Standard Model processes. This presentation provides a concise introduction to quantum computing before delving into recent advancements that pave the way for first-principles simulations of the non-perturbative dynamics within the strong interaction. Highlighting a few compelling outcomes, the discussion concludes with a forward-looking perspective on potential breakthroughs in the coming decade.</p
Visit by Mr Weerapong Pairsuwan, Synchrotron Light Research Institute (SLRI), Thailand
No full textVisit by Mr Weerapong Pairsuwan, Chairman, Board Executive, Synchrotron Light Research Institute (SLRI), Kingdom of Thailan