High Rate Performance of Drift Tubes

This article describes calculations and measurements of space charge effects due to high rate irradiation in high resolution drift tubes. Two main items are studied: the reduction of the gas gain and changes of the drift time. Whereas the gain reduction is similar for all gases and unavoidable, the drift time changes depend on the kind of gas that is used. The loss in resolution due to high particle rate can be minimized with a suitable gas. This behaviour is calculable, allowing predictions for new gas mixtures.Comment: 20 pages, submitted to Nuclear Instruments and Methods

A Gas Monitoring Chamber for the ATLAS Muon Monitored Drift Tube(MDT) System

The ATLAS Muon Spectrometer incorporates MDT precision chambers used for precise track reconstruction. Since the MDT resolution depends crucially on the electron drift velocity in the operating gas, a monitoring chamber is designed and constructed to precisely monitor the gas properties in real time. This chamber continuously samples the operating gas and measures the electron drift velocity in the operating gas over a wide range of electric field strength with very high resolution and short response time. In order to validate the feasibility and optimize the design, extensive simulations based on Garfield and 3D/2D finite element method(FEM) are done, which include mechanics, electrostatics, thermodynamics and computational fluid dynamics(CFD). This monitoring chamber enables the measurement of the drift velocity spectra over a varying electric field with a wide range, then very small changes and contaminations of the gas mixture can be detected. Results obtained at CERN and in the lab will be presented as well

Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR

Simulation results for future measurements of electromagnetic proton form factors at \PANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel $\bar p p \to e^+ e^-$ is studied on the basis of two different but consistent procedures. The suppression of the main background channel, $\textit{i.e.}$ $\bar p p \to \pi^+ \pi^-$, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance

Trends of credit service market development in Ukraine

Актуальність обраної теми підтверджується тим, що в Україні сформована банкоцентрична модель функціонування національного господарства, існує об’єктивна необхідність пошуку нових напрямків забезпечення стійкості банківської системи та зниження ймовірності прояву системних ризиків на основі диверсифікації напрямів діяльності банківських установ. Розширення спектра банківських послуг, що надаються клієнтам, дозволяє перерозподілити фінансові ризики, знижуючи рівень їх негативного впливу на ефективність роботи банку, сформувати нові канали надходження доходів. У результаті проведеного аналізу тенденцій розвитку банківської системи України виявлено, що з кожним роком кількість комерційних банків, які мають банківську ліцензію постійно зменшується, що в основному було спричинено важкою фінансово-економічною ситуацією в державі, кризовими явищами, веденням тимчасової адміністрації в банках та їх ліквідацією. Враховуючи високу ризиковість банківської діяльності, багато власників комерційних банків, особливо невеликих, можуть у майбутньому самоліквідуватись. У такому процесі актуалізуються питання підвищення обсягів надання кредитних послуг в Україні та зростання питомої ваги комісійних надходжень у загальній структурі доходів банківських установ. У статті проаналізовано сучасний стан розвитку ринку кредитних послуг в Україні, визначено особливості його функціонування. Оцінювання сучасного стану ринку кредитних послуг було проведено за допомогою аналізу класичних показників діяльності банківських установ в Україні, що дозволило визначити її базові особливості функціонування. Також були виявлені й труднощі проведення ґрунтовних досліджень їх надання клієнтам. Запропоновано методи впливу на ефективність процесу диверсифікації кредитних банківських послуг (визначення зовнішніх й внутрішніх умов диверсифікації кредитних банківських послуг і їх проектування на продуктову політику банку; типізація клієнтів та визначення перспективних цільових ринкових сегментів; визначення технологічних аспектів реалізації диверсифікації кредитних послуг комерційного банку; побудова прогнозних моделей продажів трансформованих продуктів та послуг комерційних банків; оцінка ефективності витрат на диверсифікацію кредитних банківських послуг).The importance of the chosen issue is confirmed by the fact that a bank-centered model of national economy functioning is formed in Ukraine, there is an objective need to find new directions for ensuring the stability of the banking system and reduce the probability of systemic risks manifestation on the basis of diversification of the banking institutions activity. Expansion of the banking services range provided to the customers makes it possible to redistribute financial risks, reducing the level of their negative impact on the bank operating efficiency, to form new revenue streams. Analysis of the trends of banking system development in Ukraine shows that every year the number of commercial banks having banking license is steadily decreasing, mainly as the result of difficult financial and economic situation in the country, crisis phenomena, temporary bank administration introduction and its dissolution. Taking into account high riskiness of banking activities, many commercial bank owners, especially small ones, can self-dissolve in the future. In such process, the problems of credit services volume increase in Ukraine and the growth of commission share in general income structure of banking institutions become actual. The current state of credit services market development in Ukraine is analyzed, the peculiarities of its functioning are identified in this paper. The evalution of the current state of credit services market is carried out due to the analysis of classical indicators of banking institutions activities in Ukraine making it possible to determine its basic functioning features. However, the difficulties of carrying out the profound research of their provision to the customers are also identified. Based on this, the methods of influence on the efficiency of credit banking services diversification process (definition of external and internal conditions of credit banking services diversification and their design on the bank product policy; customers typification and determination of promising target market segments; determination of technological aspects for implementation the commercial bank credit services diversification; construction of forecasting models for sales of commercial banks transformed products and services; estimation of cost effectiveness for credit banking services diversification) are proposed

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured