3,313 research outputs found

    Effects of ATLAS Tile calorimeter failures on jets and missing transverse energy measurements

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    Failures of the ATLAS Tile calorimeter would affect the jet energy resolution and would fake tails of missing transverse energy. Significant effects are expected in processes involving high transverse momentum jets (pT>100p_T > 100 GeV). These effects, their consequences, as well as methods to minimize them, are studied using simulated data for various degradation topologies and for different physics processes

    Integral Functionals of the Gasser–Muller Regression Function

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    For integral functionals of the Gasser–Muller regression function and its derivatives, we consider the plug-in estimator. The consistency and asymptotic normality of the estimator are shown.Для інтегральних функцiоналiв Функції регресії Гассера-Мюллера та їх похідних розглядається оцінка, що підключається. Встановлено обґрунтованість та асимптотичну нормальність цієї оцінки

    TileCal TDAQ/DCS communication

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    This document describes the communication between the TDAQ and DCS systems of the Hadronic Tile Calorimeter detector of the ATLAS experiment, currently under commissioning phase at CERN. It is a further step on the TDAQ and DCS communication for TileCal operation. The aim of the implementation is to increase the robustness and understanding of the detector from the two systems involved. The basic principle observed is that the two systems operate independently in parallel. Hence, the knowledge of the status of the whole detector from each of the two systems is required for further analysis of the archived data

    A mobile data acquisition system

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    A mobile data aquisition (MobiDAQ) was developed for the ATLAS central hadronic calorimeter (TileCal). MobiDAQ has been designed in order to test the functionalities of the TileCal front-end electronics and to acquire calibration data before the final back-end electronics were built and tested. MobiDAQ was also used to record the first cosmic ray events acquired by an ATLAS subdetector in the underground experimental area

    A monitoring method for the Low Voltage Power Supply modules of the ATLAS Tile Calorimeter

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    We present a method for testing the operational stability of Low Voltage Power Supply modules of the ATLAS Tile Calorimeter, based on a self-consistent determination of the stability criteria. The recorded voltage, current, and temperature values of each module are retrieved from the Oracle database for a long and smooth running period and their mean and RMS values over that period are determined, as well as their average recording rates, by taking into account the â??smoothingâ?? procedure which is applied during data recording to reduce data storage. The average behavior of the ensemble of all modules is determined from those time-integrated quantities and the modules are then tested one-by-one by comparing with the ensemble averages. The proposed method is tested for all Long Barrel modules operated during April of 2007

    Production of (super)heavy quarkonia and new Higgs physics at hadron colliders

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    Based on the two Higgs doublet model, we study the effect of Higgs-boson exchange on the (super)heavy quarkonium \bar QQ, which induces a strong attractive force between a (super)heavy quark Q and an antiquark \bar Q. An interesting application is the decay of (super)heavy quarkonia \bar QQ into a Higgs boson associated with gauge bosons. The criterion for making the \bar QQ bound state is studied. We also show that non-perturbative effects due to gluonic field fluctuations are rather small in such a heavy quark sector. Possible enhancement for productions and decays of \bar QQ bound states made from the fourth generation quark Q is discussed for \bar p p (at the Tevatron) and pp (at the LHC) collisions.Comment: 18 pages, REVTeX, 9 figures. V2: minor changes, references and acknowledgments adde

    Peripheral vascular lesions with the development of hand and foot skin necrosis in a patient with COVID-19: a case report

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    In the presented case report, 36-year-old female patient, who was hospitalized in the rheumatology department, developed thrombotic microangiopathy and sepsis-related coronavirus disease 2019 (COVID-19). In the department, hereditary thrombophilia was revealed: heterozygous polymorphism in the coagulation factor 5 gene (Factor V Leiden). Livedo reticularis. It is known that in October 2020, the patient had COVID-19 with bilateral pneumonitis on chest computed tomography. On examination, dry gangrene of 1, 2, 4, 5 fingers of the right hand, 2 finger of the left hand, as well as 2, 3, 4, 5 fingers of the right and left feet were diagnosed. Necrosis of the nasal tip. Surgery was performed with amputation of the affected fingers and distal feet with autodermoplasty

    Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb−1 of pp collisions at s=13TeV with the ATLAS experiment

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    A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb−1 of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqγ coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tuγ coupling of 36 fb (78 fb) and on the branching ratio for t→γu of 2.8×10−5 (6.1×10−5). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tcγ coupling of 40 fb (33 fb) and on the branching ratio for t→γc of 22×10−5 (18×10−5)