515664 research outputs found
Sort by
Guidelines for FPGA Gateware Development in LHCb
No full textThis technical note outlines best practices and methodologies for FPGA develop- ment, with a focus on coding standards, verification techniques, and reusable design components tailored for LHCb gateware community. It introduces coding guidelines to ensure consistency, readability, and maintainability in FPGA designs, followed by an exploration of simulation methods and formal verification techniques to guarantee functional correctness and comprehensive coverage. The colibri library is presented as a standardized collection of reusable components, enabling portability and re-liability across diverse applications. Additionally, the integration of testbenches into Continuous Integration pipelines is discussed, providing automated testing and feedback to maintain code quality throughout the development lifecycle. By combining these approaches, the technical note aims to establish a robust framework for efficient and reliable FPGA development, fostering collaboration and innovation within the LHCb community
Measurement of substructure-dependent suppression of large-radius jets with charged particles in Pb+Pb collisions with ATLAS
No full textMeasurements of jet substructure in Pb+Pb collisions provide key insights into the mechanism of jet quenching in the hot and dense QCD medium created in these collisions. This Letter presents a measurement of the suppression of large-radius jets with a radius parameter of and its dependence on the jet substructure. The measurement uses 1.72 nb of Pb+Pb data and 255 pb of data, both at TeV, recorded with the ATLAS detector at the Large Hadron Collider. Large-radius jets are reconstructed by reclustering calorimetric jets and are measured for transverse momentum above GeV. Jet substructure is evaluated using charged-particle tracks, and the overall level of jet suppression is quantified using the jet nuclear modification factor (). The jet is measured as a function of jet , the charged splitting scale (), and the angular separation () of two leading sub-jets. The jet gradually decreases with increasing , implying significantly stronger suppression of large-radius jets with larger splitting scale. The jet gradually decreases for in the range and then remains consistent with a constant for . The observed significant dependence of jet suppression on the jet substructure will provide new insights into its role in the quenching process.Measurements of jet substructure in Pb+Pb collisions provide key insights into the mechanism of jet quenching in the hot and dense QCD medium created in these collisions.This Letter presents a measurement of the suppression of large-radius jets with a radius parameter of R=1.0 and its dependence on the jet substructure. The measurement uses 1.72 nb−1 of Pb+Pb data and 255 pb−1 of pp data, both at sNN=5.02 TeV, recorded with the ATLAS detector at the Large Hadron Collider. Large-radius jets are reconstructed by reclustering R=0.2 calorimetric jets and are measured for transverse momentum above 200 GeV. Jet substructure is evaluated using charged-particle tracks, and the overall level of jet suppression is quantified using the jet nuclear modification factor (RAA). The jet RAA is measured as a function of jet pT, the charged kt splitting scale (d12), and the angular separation (ΔR12) of two leading sub-jets. The jet RAA gradually decreases with increasing d12, implying significantly stronger suppression of large-radius jets with larger kt splitting scale. The jet RAA gradually decreases for ΔR12 in the range 0.01−0.2 and then remains consistent with a constant for ΔR12 ≳ 0.2. The observed significant dependence of jet suppression on the jet substructure will provide new insights into its role in the quenching process.Measurements of jet substructure in Pb+Pb collisions provide key insights into the mechanism of jet quenching in the hot and dense QCD medium created in these collisions. This Letter presents a measurement of the suppression of large-radius jets with a radius parameter of and its dependence on the jet substructure. The measurement uses 1.72 nb of Pb+Pb data and 255 pb of data, both at TeV, recorded with the ATLAS detector at the Large Hadron Collider. Large-radius jets are reconstructed by reclustering calorimetric jets and are measured for transverse momentum above GeV. Jet substructure is evaluated using charged-particle tracks, and the overall level of jet suppression is quantified using the jet nuclear modification factor (). The jet is measured as a function of jet , the charged splitting scale (), and the angular separation () of two leading sub-jets. The jet gradually decreases with increasing , implying significantly stronger suppression of large-radius jets with larger splitting scale. The jet gradually decreases for in the range and then remains consistent with a constant for . The observed significant dependence of jet suppression on the jet substructure will provide new insights into its role in the quenching process
Search Long-lived Particles in ATLAS
No full textTalk for MoriondQCD2025 with the following topics (ATLAS-only): Search MS for displaced jets in the muon spectrometer EXOT-2022-17 and search for heavy neutral leptons (HNL) with displaced vertices EXOT-2022-12
Expected performance of the ALPIDE pixel layers in ALICE FoCal
No full textThe ALICE experiment is designed to study ultra-relativistic heavy-ion collisions at the Large Hadron Collider (LHC). As part of its major upgrades for Run 4, the Forward Calorimeter (FoCal) will be installed during Long Shutdown 3 (LS3). FoCal enables precise measurements of direct photon production at forward rapidity, providing a sensitive probe of the gluon distribution in protons and nuclei. This paper introduces the expected performance of forward electromagnetic calorimeter (FoCal-E) and presents several potential strategies for mitigating occupancy and BUSY violation challenges in the pixel layers of FoCal-E. Beam test results demonstrate that back biasing effectively reduces pixel occupancy. Meanwhile, SystemC simulations explore additional mitigation strategies — such as grid masking and a regional trigger — to further minimize BUSY violations and enhance detector performance under high-luminosity conditions.The ALICE experiment is designed to study ultra-relativistic heavy-ion collisions at the Large Hadron Collider (LHC). As part of its major upgrades for Run 4, the Forward Calorimeter (FoCal) will be installed during Long Shutdown 3 (LS3). FoCal enables precise measurements of direct photon production at forward rapidity, providing a sensitive probe of the gluon distribution in protons and nuclei. This paper introduces the expected performance of the forward electromagnetic calorimeter (FoCal-E) and presents several potential strategies for mitigating occupancy and BUSY violation challenges in the pixel layers of FoCal-E. Beam test results demonstrate that back biasing effectively reduces pixel occupancy. Meanwhile, SystemC simulations explore additional mitigation strategies-such as grid masking and a regional trigger-to further minimize BUSY violations and enhance detector performance under high-luminosity conditions
Differential measurements of using TeV Pb+Pb collisions with the ATLAS detector
No full textThis study presents differential fiducial cross-section measurements of photon-induced -lepton pair production. The results are obtained using ultraperipheral lead-lead collisions recorded in 2015 and 2018 at TeV by the ATLAS experiment at the LHC. The dataset corresponds to an integrated luminosity of 1.93 nb. Events are selected using topologies with one of the -leptons decaying to a muon and two neutrinos and by the presence of an electron or charged-particle track(s) from the second -lepton decay. Events with low activity in the zero-degree calorimeters are used, corresponding to a topology without forward neutron emissions. The data are corrected for detector-related effects through an iterative Bayesian unfolding procedure, obtaining differential fiducial cross-sections at particle level for seven kinematic variables of the -lepton decay products for each of the three considered final state categories
Contribution of ALEGRO to the Update of the European Strategy on Particle Physics
No full textAdvanced and novel accelerators (ANAs), driven a by laser pulse or a relativistic particle bunch, have made remarkable progress over the last decades. They accelerated electrons by 10GeV in 30cm (laser driven) and by 42GeV in 85cm (particle bunch driven). Rapid progress continues with lasers, plasma sources, computational methods, and more. In this document we highlight the main contributions made by the various major collaborations, facilities, and experiments that develop ANAs for applications to particle and high-energy physics. These include: ALiVE, ANL-AWA, AWAKE, BNL-ATF, CEPC Injector, DESY-KALDERA, ELI ERIC, EuPRAXIA, HALHF, LBNL-BELLA, LBNL-kBELLA, LCvison, PETRA IV Injector, 10TeV Collider design, SLAC-FACET II, as well as the development of structures, lasers and plasma sources, and sustainability, and demonstrate the intense activities in the field. ANAs can have, and already have, applications to particle and high-energy physics as subsystems, the so-called intermediate applications: injectors, lower energy experiments, beam dump experiments, test beds for detectors, etc. Additionally, an ANA could be an upgrade for any Higgs factory based on a linear accelerator, as proposed in the LCvison project. ANAs have advantages over other concepts for reaching multi-TeV energies: lower geographical and environmental footprints, higher luminosity to power ratio, and are thus more sustainable than other accelerators. However, ANAs must still meet a number of challenges before they can produce bunches with parameters and the luminosity required for a linear collider at the energy frontier. It is therefore extremely important to strongly support vigorous R&D of ANAs, because they are, at this time, the most sustainable acceleration scheme to reach very high energies with a linear accelerator