A5057189760- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Distributed and Parallel Computing Systems
- Black Holes and Theoretical Physics
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Medical Imaging Techniques and Applications
- Advanced Data Storage Technologies
- Particle Accelerators and Free-Electron Lasers
- Scientific Computing and Data Management
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- advanced mathematical theories
- Algorithms and Data Compression
- Muon and positron interactions and applications
- Big Data Technologies and Applications
- Scientific Research and Discoveries
- Particle accelerators and beam dynamics
- Electron and X-Ray Spectroscopy Techniques
European Organization for Nuclear Research
2016-2025
Northern Illinois University
2020-2024
Institute for High Energy Physics
2023-2024
Institute of Science and Technology
2023-2024
Atlas Scientific (United States)
2024
SR Research (Canada)
2024
Federación Española de Enfermedades Raras
2024
Institute of High Energy Physics
1996-2024
A. Alikhanyan National Laboratory
2024
The University of Adelaide
2014-2023
During the shutdown of CERN Large Hadron Collider in 2013-2014, an additional pixel layer was installed between existing Pixel detector ATLAS experiment and a new, smaller radius beam pipe. The motivation for this new layer, Insertable B-Layer (IBL), to maintain or improve robustness performance tracking system, given higher instantaneous integrated luminosities realised following shutdown. Because extreme radiation collision rate environment, several radiation-tolerant sensor electronic...
The ATLAS collaboration will upgrade its semiconductor pixel tracking detector with a new Insertable B-layer (IBL) between the existing and vacuum pipe of Large Hadron Collider. extreme operating conditions at this location have necessitated development radiation hard sensor technologies front-end readout chip, called FE-I4. Planar sensors 3D been investigated to equip layer, prototype modules using FE-I4A fabricated characterized 120 GeV pions CERN SPS 4 positrons DESY, before after module...
Abstract The reconstruction of the trajectories charged particles, or track reconstruction, is a key computational challenge for particle and nuclear physics experiments. While tuning algorithms can depend strongly on details detector geometry, currently in use by experiments share many common features. At same time, intense environment High-Luminosity LHC accelerator other future expected to put even greater stress software, motivating development more performant algorithms. We present here...
Rucio is an open-source software framework that provides scientific collaborations with the functionality to organize, manage, and access their data at scale. The can be distributed across heterogeneous centers widely locations. was originally developed meet requirements of high-energy physics experiment ATLAS, now continuously extended support LHC experiments other diverse communities. In this article, we detail fundamental concepts Rucio, describe architecture along implementation details,...
The nature of b-quark jet hadronisation has been investigated using data taken at the Z peak by DELPHI detector LEP. Two complementary methods are used to reconstruct energy weakly decaying b-hadrons, $E_{\mathrm{B}}^{\mathrm{weak}}$ . average value $x^{\mathrm{weak}}_{\mathrm{B}} = E_{\mathrm{B}}^{\mathrm{weak}}/E_{\mathrm{beam}}$ is measured be 0.699±0.011. resulting $x^{\mathrm{weak}}_{\mathrm{B}}$ distribution then analysed in framework two choices for perturbative contribution (parton...
The track reconstruction of modern high energy physics experiments is a very complex task that puts stringent requirements onto the software realisation. ATLAS has been in past dominated by collection individual packages, each which incorporating different intrinsic event data model, flow sequences and calibration data. Recently, undergone major design revolution to ensure maintainability during long lifetime experiment flexibility needed for startup phase. entire chain re-organised modular...
Single photons detected by the DELPHI experiment at LEP2 in years 1997–2000 are reanalysed to investigate existence of a single extra dimension modified ADD scenario with slightly warped large dimensions. The data collected centre-of-mass energies between 180 and 209 GeV for an integrated luminosity ∼650 pb−1 agree predictions Standard Model allow limit be set on graviton emission one dimension. obtained fundamental mass scale M D is 1.69 TeV/c 2 95% CL, expected 1.71 2.
A determination of the single W spin density matrix (SDM) elements in reaction e+e-→W+W-→lνqq̄(l=e/μ) is reported at centre-of-mass energies between 189 and 209 GeV. The data sample used corresponds to an integrated luminosity 520 pb-1 taken by DELPHI 1998 2000. SDM elements, ρττ' W± (τ,τ'=± 1 or 0), are determined as a function W- production angle with respect e- beam direction obtained from measurements decay products application suitable projection operators, Λττ', which assume V-A...
During the 2013-2014 shutdown of Large Hadron Collider, ATLAS switched to a new event data model for analysis, called xAOD. A key feature this is separation object from objects themselves (the 'auxiliary store'). Rather than being stored as member variables analysis classes, all are separately, vectors simple values. Thus, in 'structure arrays' format, while user still can access it an 'array structures'. This organization allows on-demand partial reading objects, selective removal...
While many high energy experiments use track fitting software that is based solely on the Kalman Filter technique, ATLAS offline reconstruction also has several global fitters available. One of these GlobalChi2Fitter, which scattering angle formulation fit. advantages this method over fit it can provide angles and related quantities (e.g. residual derivatives) to alignment algorithms. The algorithm been implemented in new common tracking framework ATLAS, philosophy improve modularity...
The data taken by DELPHI at centre-of-mass energies between 189 and 209 GeV are used to place limits on the CP-conserving trilinear gauge boson couplings Delta_g1z, lambda_gamma Delta_kappag associated W+W- single W production LEP2. Using from jjlv, jjjj, jjX lX final states, where j, l X represent a jet, lepton missing four-momentum, respectively, following set when one parameter is allowed vary others their Standard Model values of zero: Delta_g1z = -0.025^{+0.033}_{-0.030},...
Within the ATLAS hierarchical, multi-tier computing infrastructure, Tier-0 centre at CERN is mainly responsible for prompt processing of raw data coming from online DAQ system, to archive and derived on tape, register with relevant catalogues distribute them associated Tier-1 centers. The already fully functional. It has been successfully participating in all cosmic commissioning taking since May 2007, was ramped up its foreseen full size, performance throughput (and short single-beam) run...
Muon bremsstrahlung photons converted in front of the DELPHI main tracker (TPC) dimuon events at LEP1 were studied two photon kinematic ranges: 0.2<E γ ≤1 GeV and transverse momentum with respect to parent muon p T <40 MeV/c, 1<E ≤10 <80 MeV/c. A good agreement observed rate predictions from QED for inner was found, contrary anomalous soft excess that has been recently hadronic Z 0 decays. The obtained ratios signal predicted level are 1.06±0.12±0.07 energy range 1.04±0.09±0.12 GeV. dead...
The reconstruction of the trajectories charged particles, or track reconstruction, is a key computational challenge for particle and nuclear physics experiments. While tuning algorithms can depend strongly on details detector geometry, currently in use by experiments share many common features. At same time, intense environment High-Luminosity LHC accelerator other future expected to put even greater stress software, motivating development more performant algorithms. We present here A Common...
An analysis of the direct soft photon production rate as a function parent jet characteristics is presented, based on hadronic events collected by DELPHI experiment at LEP1. The dependences rates kinematic (momentum, mass, etc.) and charged, neutral total hadron multiplicities are reported. Up to scale factor about four, which characterizes overall value excess, similarity observed behaviour that inner bremsstrahlung predictions found for momentum, charged multiplicity dependences. However...
Measurements are presented of R_b, the ratio b bbar cross-section to q qbar in e+e- collisions, and forward-backward asymmetry A^b_FB at twelve energy points range sqrt(s) = 130-207 GeV. These results found be consistent with Standard Model expectations. The measurements used set limits on new physics scenarios involving contact interactions.
The ATLAS High Level Trigger's (HLT) primary function of event selection will be accomplished with a Level-2 trigger farm and an filter (EF) farm, both running software components developed in the offline reconstruction framework. While this approach provides unified framework for selection, it poses strict requirements on critical trigger. A decision must typically within 10 ms multiple processing concurrent threads. To address these constraints, prototypes have been that incorporate...