Experience and performance of persistent memory for the DUNE data acquisition system

Emerging high-performance storage technologies are opening up the possibility of designing new distributed data acquisition system architectures, in which the live acquisition of data and their processing are decoupled through a storage element. An example of these technologies is 3DXPoint, which promises to fill the gap between memory and traditional storage and offers unprecedented high throughput for data persistency. In this paper, we characterize the performance of persistent memory devices, which use the 3DXPoint technology, in the context of the data acquisition system for one large Particle Physics experiment, DUNE. This experiment must be capable of storing, upon a specific signal, incoming data for up to 100 seconds, with a throughput of 1.5 TB/s, for an aggregate size of 150 TB. The modular nature of the apparatus allows splitting the problem into 150 identical units operating in parallel, each at 10 GB/s. The target is to be able to dedicate a single CPU to each of those units for data acquisition and storage.Comment: Proceedings of the IEEE RT202

Operation of the ATLAS trigger system in run 2

The ATLAS experiment at the Large Hadron Collider employs a two-level triggersystem to record data at an average rate of 1 kHz from physics collisions,starting from an initial bunch crossing rate of 40 MHz. During the LHC Run 2(2015-2018), the ATLAS trigger system operated successfully with excellentperformance and flexibility by adapting to the various run conditionsencountered and has been vital for the ATLAS Run-2 physics programme. Forproton-proton running, approximately 1500 individual event selections wereincluded in a trigger menu which specified the physics signatures and selectionalgorithms used for the data-taking, and the allocated event rate andbandwidth. The trigger menu must reflect the physics goals for a given datacollection period, taking into account the instantaneous luminosity of the LHCand limitations from the ATLAS detector readout, online processing farm, andoffline storage. This document discusses the operation of the ATLAS triggersystem during the nominal proton-proton data collection in Run 2 with examplesof special data-taking runs. Aspects of software validation, evolution of thetrigger selection algorithms during Run 2, monitoring of the trigger system anddata quality as well as trigger configuration are presented.Fil: Aad, G.. Aix-Marseille Université; FranciaFil: Abbott, B.. Oklahoma State University; Estados UnidosFil: Abbott, D.C.. University of Massachusetts; Estados UnidosFil: Abed Abud, A.. Cern - European Organization for Nuclear Research; SuizaFil: Abeling, K.. Georg-August-Universität Göttingen; AlemaniaFil: Abhayasinghe, D.K.. Royal Holloway University of London; Reino UnidoFil: Abidi, S. H.. University of Toronto; CanadáFil: AbouZeid, O. S.. Czech Academy of Sciences; República ChecaFil: Abraham, N. L.. University of Sussex; Reino UnidoFil: Abramowicz, H.. Universitat Tel Aviv; IsraelFil: Abreu, H.. Technion - Israel Institute of Technology; IsraelFil: Abreu, R.. University of Oregon; Estados UnidosFil: Abulaiti, Y.. Argonne National Laboratory; Estados UnidosFil: Acharya, B. S.. Istituto Nazionale di Fisica Nucleare; Italia. The Abdus Salam. International Centre for Theoretical Physics; ItaliaFil: Achkak, B.. Georg-August-Universität Göttingen; AlemaniaFil: Adam, L.. University of Montreal; CanadáFil: Adam Bourdarios, C.. Universite Grenoble Alpes; Francia. Université Savoie Mont Blanc; FranciaFil: Adamczyk, L.. AGH University of Science and Technology; PoloniaFil: Adamek, L.. University of Toronto; CanadáFil: Adelman, J.. Northern Illinois University; Estados UnidosFil: Adersberger, M.. Ludwig-Maximilians-Universität München; AlemaniaFil: Adiguzel, A.. Bogazici University; TurquíaFil: Adorni,S.. Université de Genève; SuizaFil: Adye, T.. Universite Paris-Saclay;Fil: Affolder, A. A.. University of California Santa Cruz; Estados UnidosFil: Afik, Y.. Technion - Israel Institute of Technology; IsraelFil: Agapopoulou, C.. Universite Paris-Saclay;Fil: Agaras, M. N.. Université Clermont Auvergne; Francia. Centre National de la Recherche Scientifique; FranciaFil: Aggarwal, A.. Radboud Universiteit Nijmegen; Países BajosFil: Orellana, Gonzalo Enrique. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentin

Measurement of VH, H→bb¯ production as a function of the vector-boson transverse momentum in 13 TeV pp collisions with the ATLAS detector

Cross-sections of associated production of a Higgs boson decaying into bottom-quark pairs and an electroweak gauge boson, W or Z, decaying into leptons are measured as a function of the gauge boson transverse momentum. The measurements are performed in kinematic fiducial volumes defined in the `simplified template cross-section´ framework. The results are obtained using 79.8 fb−1 of proton-proton collisions recorded by the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 13 TeV. All measurements are found to be in agreement with the Standard Model predictions, and limits are set on the parameters of an effective Lagrangian sensitive to modifications of the Higgs boson couplings to the electroweak gauge bosons.Fil: Aaboud, M.. Université Mohamed; MarruecosFil: Aad, G.. Aix-Marseille Université; Francia. Centre National de la Recherche Scientifique; FranciaFil: Abbott, B.. University of Oklahoma; Estados UnidosFil: Abbott, D. C.. University of Oklahoma; Estados UnidosFil: Abdinov, O.. Azerbaijan Academy of Sciences; AzerbaiyánFil: Abed Abud, A.. Universita degli Studi di Pavia; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Abhayasinghe, D. K.. Royal Holloway University of London; Reino UnidoFil: Abidi, S. H.. University of Toronto; CanadáFil: AbouZeid, O. S.. Universidad de Copenhagen; DinamarcaFil: Abraham, N. L.. University of Sussex; Reino UnidoFil: Abramowicz, H.. Universitat Tel Aviv; IsraelFil: Abreu, H.. Technion - Israel Institute of Technology; IsraelFil: Abulaiti, Y.. Argonne National Laboratory; Estados UnidosFil: Acharya, B. S.. Istituto Nazionale di Fisica Nucleare; Italia. The Abdus Salam. International Centre for Theoretical Physics; Italia. King’s College London; Reino UnidoFil: Adachi, S.. University of Tokyo; JapónFil: Adam, L.. Universität Mainz; AlemaniaFil: Adam Bourdarios, C.. Université Paris-Sud; Francia. Universite Paris-Saclay; . Centre National de la Recherche Scientifique; FranciaFil: Adamczyk, L.. University of Science and Technology; PoloniaFil: Adamek, L.. University of Toronto; CanadáFil: Adelman, J.. Northern Illinois University; Estados UnidosFil: Adersberger, M.. Ludwig-Maximilians-Universität München; AlemaniaFil: Adiguzel, A.. Bogazici University; Turquía. Istanbul University; TurquíaFil: Adorni, S.. Université de Genève; FranciaFil: Adye, T.. Rutherford Appleton Laboratory; Reino UnidoFil: Affolder, A. A.. University of California Santa Cruz; Estados UnidosFil: Afik, Y.. Technion - Israel Institute of Technology; IsraelFil: Agapopoulou, C.. Université Paris-Sud; Francia. Centre National de la Recherche Scientifique; Francia. Universite Paris-Saclay;Fil: Agaras, M. N.. Université Clermont Auvergne; Francia. Centre National de la Recherche Scientifique; FranciaFil: Aggarwal, A.. Radboud Universiteit Nijmegen; Países BajosFil: Arduh, Francisco Anuar. Cern - European Organization for Nuclear Research; Suiza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentin

Measurement of soft-drop jet observables in p p collisions with the ATLAS detector at s = 13TeV

Jet substructure quantities are measured using jets groomed with the soft-drop grooming procedure in dijet events from 32.9 fb−1 of pp collisions collected with the ATLAS detector at s=13 TeV. These observables are sensitive to a wide range of QCD phenomena. Some observables, such as the jet mass and opening angle between the two subjets which pass the soft-drop condition, can be described by a high-order (resummed) series in the strong coupling constant αS. Other observables, such as the momentum sharing between the two subjets, are nearly independent of αS. These observables can be constructed using all interacting particles or using only charged particles reconstructed in the inner tracking detectors. Track-based versions of these observables are not collinear safe, but are measured more precisely, and universal non-perturbative functions can absorb the collinear singularities. The unfolded data are directly compared with QCD calculations and hadron-level Monte Carlo simulations. The measurements are performed in different pseudorapidity regions, which are then used to extract quark and gluon jet shapes using the predicted quark and gluon fractions in each region. All of the parton shower and analytical calculations provide an excellent description of the data in most regions of phase space.Fil: Aad, G.. Aix-Marseille Université; FranciaFil: Abbott, B.. Ochanomizu University; JapónFil: Abbott, D. C.. University of Massachusetts; Estados UnidosFil: Abed Abud, A.. Cern - European Organization for Nuclear Research; SuizaFil: Abeling, K.. Georg August Universität Göttingen; AlemaniaFil: Abhayasinghe, D. K.. Royal Holloway University of London; Reino UnidoFil: Abidi, S. H.. University of Toronto; CanadáFil: AbouZeid, O. S.. University of Copenhagen; DinamarcaFil: Abraham, N. L.. University of Sussex; Reino UnidoFil: Abramowicz ,H.. Universitat Tel Aviv; IsraelFil: Abreu, H.. Technion - Israel Institute of Technology; IsraelFil: Abulaiti, Y.. Argonne National Laboratory; Estados UnidosFil: Acharya, B. S.. The Abdus Salam. International Centre for Theoretical Physics; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Achkar, B.. Georg August Universität Göttingen; AlemaniaFil: Adachi,S.. University of Tokyo; JapónFil: Adam, L.. Technion - Israel Institute of Technology; IsraelFil: Adam Bourdarios, C.. Universite Grenoble Alpes; Francia. Université Savoie Mont Blanc; FranciaFil: Adamczyk, L.. AGH University of Science and Technology; PoloniaFil: Adamek, L.. University of Toronto; CanadáFil: Adelman, J.. Northern Illinois University; Estados UnidosFil: Adersberger, M.. Ludwig-Maximilians-Universität München; AlemaniaFil: Adiguzel, A.. Bahcesehir University; TurquíaFil: Adorni, S.. Université de Genève; SuizaFil: Adye, T.. Rutherford Appleton Laboratory; Reino UnidoFil: Affolder, A. A.. University of California Santa Cruz; Estados UnidosFil: Afik, Y.. Technion - Israel Institute of Technology; IsraelFil: Agapopoulou, C.. Universite Paris-Saclay; . Centre National de la Recherche Scientifique; FranciaFil: Agaras, M. N.. Université Clermont Auvergne; Francia. Centre National de la Recherche Scientifique; FranciaFil: Aggarwal, A.. Radboud Universiteit Nijmegen; Países BajosFil: Piegaia, Ricardo Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

Operation and performance of the ATLAS semiconductor tracker in LHC Run 2

The semiconductor tracker (SCT) is one of the tracking systems for charged particles in the ATLAS detector. It consists of 4088 silicon strip sensor modules. During Run 2 (2015–2018) the Large Hadron Collider delivered an integrated luminosity of 156 fb−1 to the ATLAS experiment at a centre-of-mass proton-proton collision energy of 13 TeV. The instantaneous luminosity and pile-up conditions were far in excess of those assumed in the original design of the SCT detector. Due to improvements to the data acquisition system, the SCT operated stably throughout Run 2. It was available for 99.9% of the integrated luminosity and achieved a data-quality efficiency of 99.85%. Detailed studies have been made of the leakage current in SCT modules and the evolution of the full depletion voltage, which are used to study the impact of radiation damage to the modules.The Atlas Collaboration ... G. Aad ... Paul D. Jackson ... Albert X. Kong ... Harish Potti ... Tristan A. Ruggeri ... Martin White ... et al

Measurements of top-quark pair single- and double-differential cross-sections in the all-hadronic channel in pp collisions at root s = 13 TeV using the ATLAS detector

Differential cross-sections are measured for top-quark pair production in the all-hadronic decay mode, using proton-proton collision events collected by the ATLAS experiment in which all six decay jets are separately resolved. Absolute and normalised single- and double-differential cross-sections are measured at particle and parton level as a function of various kinematic variables. Emphasis is placed on well-measured observables in fully reconstructed final states, as well as on the study of correlations between the top-quark pair system and additional jet radiation identified in the event. The study is performed using data from proton-proton collisions at s√ = 13 TeV collected by the ATLAS detector at CERN’s Large Hadron Collider in 2015 and 2016, corresponding to an integrated luminosity of 36.1 fb−1. The rapidities of the individual top quarks and of the top-quark pair are well modelled by several independent event generators. Significant mismodelling is observed in the transverse momenta of the leading three jet emissions, while the leading top-quark transverse momentum and top-quark pair transverse momentum are both found to be incompatible with several theoretical predictions.G. Aad, B. Abbott, D. C. Abbott, A. Abed Abud, K. Abeling ... Paul Jackson ... et al (The ATLAS collaboration

Search for Higgs boson production in association with a high-energy photon via vector-boson fusion with decay into bottom quark pairs at root s= 13 TeV with the ATLAS detector

A search is presented for the production of the Standard Model Higgs boson in association with a high-energy photon. With a focus on the vector-boson fusion process and the dominant Higgs boson decay into b-quark pairs, the search benefits from a large reduction of multijet background compared to more inclusive searches. Results are reported from the analysis of 132 fb−1 of pp collision data at s√ = 13 TeV collected with the ATLAS detector at the LHC. The measured Higgs boson signal yield in this final-state signature is 1.3 ± 1.0 times the Standard Model prediction. The observed significance of the Higgs boson signal above the background is 1.3 standard deviations, compared to an expected significance of 1.0 standard deviations.G. Aad … Paul Jackson … Albert Kong … Tristan Ruggeri … Martin White … Harish Potti … et al

Search for squarks and gluinos in final states with one isolated lepton, jets, and missing transverse momentum at √s = 13 TeV with the ATLAS detector

The results of a search for gluino and squark pair production with the pairs decaying via the lightest charginos into a final state consisting of two W bosons, the lightest neutralinos ((χ~01)), and quarks, are presented: the signal is characterised by the presence of a single charged lepton (e(±) or μ(±)) from a W boson decay, jets, and missing transverse momentum. The analysis is performed using 139 fb⁻¹ of proton–proton collision data taken at a centre-of-mass energy √s = 13 delivered by the Large Hadron Collider and recorded by the ATLAS experiment. No statistically significant excess of events above the Standard Model expectation is found. Limits are set on the direct production of squarks and gluinos in simplified models. Masses of gluino (squark) up to 2.2 (1.4 ) are excluded at 95% confidence level for a light (χ~01).G. Aad … D. Duvnjak … P. Jackson … A.X.Y. Kong … J.L. Oliver … H. Potti … T.A. Ruggeri … A.S. Sharma … M.J. White … et al. [The ATLAS Collaboration

Search for supersymmetry in events with four or more charged leptons in 139 fb(-1) of root s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry in events with four or more charged leptons (electrons, muons and τ-leptons) is presented. The analysis uses a data sample corresponding to 139 fb⁻¹ of proton-proton collisions delivered by the Large Hadron Collider at s√ = 13 TeV and recorded by the ATLAS detector. Four-lepton signal regions with up to two hadronically decaying τ-leptons are designed to target several supersymmetric models, while a general five-lepton signal region targets any new physics phenomena leading to a final state with five charged leptons. Data yields are consistent with Standard Model expectations and results are used to set upper limits on contributions from processes beyond the Standard Model. Exclusion limits are set at the 95% confidence level in simplified models of general gauge-mediated supersymmetry, excluding higgsino masses up to 540 GeV. In R-parity-violating simplified models with decays of the lightest supersymmetric particle to charged leptons, lower limits of 1.6 TeV, 1.2 TeV, and 2.5 TeV are placed on wino, slepton and gluino masses, respectively.G. Aad … D. Duvnjak … P. Jackson … A.X.Y. Kong … J.L. Oliver … H. Potti … A. Qureshi … A.S. Sharma … M.J. White … et al. [The ATLAS Collaboration