Belle II grid-based user analysis Bennett, J V; Guilliams, J; M Hernandez Villanueva ...
arXiv (Cornell University),
03/2022
Paper, Journal Article
Odprti dostop
The Belle II experiment at the SuperKEKB accelerator is a next-generation B-factory aiming to collect 50 ab\(^{-1}\), about 50 times the data collected at Belle, to study rare processes and make ...precision measurements that may expose physics beyond the Standard Model. Corresponding to roughly 100 PB of storage for raw data, plus dozens of PBs per year for Monte Carlo (MC) and analysis data, these massive samples require careful planning for the storage, processing, and analysis of data. This white paper notes some of the challenges that await grid-based user-analysis at the intensity frontier and invites further discussion and exploration to improve the tools and techniques necessary to leverage the massive data samples that will be available at Belle II as part of the Snowmass process.
The construction of the ATLAS electromagnetic liquid argon calorimeter modules is completed and all the modules are assembled and inserted in the cryostats. During the production period four barrel ...and three endcap modules were exposed to test beams in order to assess their performance, ascertain the production quality and reproducibility, and to scrutinize the complete energy reconstruction chain from the readout and calibration electronics to the signal and energy reconstruction. It was also possible to check the full Monte Carlo simulation of the calorimeter. The analysis of the uniformity, resolution and extraction of constant term is presented. Typical non-uniformities of 0.5% and typical global constant terms of 0.6% are measured for the barrel and end-cap modules.
Nucl.Instrum.Meth.A531:481-514,2004 A full azimuthal phi-wedge of the ATLAS liquid argon end-cap calorimeter has
been exposed to beams of electrons, muons and pions in the energy range 6 GeV
<= E <= ...200 GeV at the CERN SPS. The angular region studied corresponds to the
ATLAS impact position around the pseudorapidity interval 1.6 < |eta| < 1.8. The
beam test set-up is described. A detailed study of the performance is given as
well as the related intercalibration constants obtained. Following the ATLAS
hadronic calibration proposal, a first study of the hadron calibration using a
weighting ansatz is presented. The results are compared to predictions from
Monte Carlo simulations, based on GEANT 3 and GEANT 4 models.
A full azimuthal phi-wedge of the ATLAS liquid argon end-cap calorimeter has been exposed to beams of electrons, muons and pions in the energy range 6 GeV <= E <= 200 GeV at the CERN SPS. The angular ...region studied corresponds to the ATLAS impact position around the pseudorapidity interval 1.6 < |eta| < 1.8. The beam test set-up is described. A detailed study of the performance is given as well as the related intercalibration constants obtained. Following the ATLAS hadronic calibration proposal, a first study of the hadron calibration using a weighting ansatz is presented. The results are compared to predictions from Monte Carlo simulations, based on GEANT 3 and GEANT 4 models.
A search for a narrow scalar resonance decaying into an opposite-sign muon pair produced in events with and without b-tagged jets is presented in this paper. The search uses 36.1 fb−1 of s√=13 TeV ...proton-proton collision data recorded by the ATLAS experiment at the LHC. No significant excess of events above the expected Standard Model background is observed in the investigated mass range of 0.2 to 1.0 TeV. The observed upper limits at 95% confidence level on the cross section times branching ratio for b-quark associated production and gluon-gluon fusion are between 1.9 and 41 fb and 1.6 and 44 fb respectively, which is consistent with expectations.
A measurement of the associated production of a top-quark pair (t¯t) with a vector boson (W, Z) in proton-proton collisions at a center-of-mass energy of 13 TeV is presented, using 36.1 fb−1 of ...integrated luminosity collected by the ATLAS detector at the Large Hadron Collider. Events are selected in channels with two same- or opposite-sign leptons (electrons or muons), three leptons or four leptons, and each channel is further divided into multiple regions to maximize the sensitivity of the measurement. The t¯tZ and t¯tW production cross sections are simultaneously measured using a combined fit to all regions. The best-fit values of the production cross sections are σt¯tZ ¼ 0.95 0.08stat 0.10syst pb and σt¯tW ¼ 0.87 0.13stat 0.14syst pb in agreement with the Standard Model predictions. The measurement of the t¯tZ cross section is used to set constraints on effective field theory operators which modify the t¯tZ vertex.
Inclusive and differential cross-sections for the production of a top-quark pair in association with a photon are measured with proton-proton collision data corresponding to an integrated luminosity ...of 36.1 fb−1, collected by the ATLAS detector at the LHC in 2015 and 2016 at a centreof-mass energy of 13 TeV. The measurements are performed in single-lepton and dilepton final states in a fiducial volume. Events with exactly one photon, one or two leptons, a channel-dependent minimum number of jets, and at least one b-jet are selected. Neural network algorithms are used to separate the signal from the backgrounds. The fiducial cross-sections are measured to be 521±9(stat.)±41(sys.) fb and 69 ± 3(stat.) ± 4(sys.) fb for the single-lepton and dilepton channels, respectively. The differential cross-sections are measured as a function of photon transverse momentum, photon absolute pseudorapidity, and angular distance between the photon and its closest lepton in both channels, as well as azimuthal opening angle and absolute pseudorapidity difference between the two leptons in the dilepton channel. All measurements are in agreement with the theoretical predictions.
ATLAS est une quatre des experiences en cours de construction sur le futur collisionneur proton-proton du CERN, le LHC. Cette experience a un programme de physique generaliste allant du Modele ...Standard a la recherche de nouvelle physique. La recherche d'un boson de Higgs se desintegrant en deux photons ou quatre electrons, ou celle de Z' ou W' necessite une bonne resolution en energie du calorimetre electromagnetique.
Cette these decrit les tests en faisceau realises sur trois des modules des bouchons du calorimetre electromagnetique d'ATLAS. Une non-uniformite de 0.6% est obtenue sur ces trois modules, ainsi qu'un terme constant global de resolution en energie de 0.7% (terme
dominant a haute energie). Par ailleurs, une etude sur la separation entre electrons et jets est egalement menee. Cette etude montre qu'un facteur de rejet sur les jets d'environ $10^5$ peut etre atteint en conservant une efficacite de selection des electrons superieure a 78%.
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