A search for a Higgs boson has been performed in the H→WW→ℓνjj channel in 1.04 fb−1 of pp collision data at s=7 TeV recorded with the ATLAS detector at the Large Hadron Collider. No significant excess of events i...
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A search for a Higgs boson has been performed in the H→WW→ℓνjj channel in 1.04 fb−1 of pp collision data at s=7 TeV recorded with the ATLAS detector at the Large Hadron Collider. No significant excess of events is observed over the expected background and limits on the Higgs boson production cross section are derived for a Higgs boson mass in the range 240 GeV
This paper proposes a control strategy for a Diesel Oxidation Catalyst (DOC) which is grounded on a one-dimensional distributed parameter model. This first principles model for the propagation of the temperature varia...
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ISBN:
(纸本)9783902661548
This paper proposes a control strategy for a Diesel Oxidation Catalyst (DOC) which is grounded on a one-dimensional distributed parameter model. This first principles model for the propagation of the temperature variations accounts for spatially distributed heat generation (due to oxidation of reductants). As is discussed, heat generation can be regarded as equivalent inlet temperature variations. This fact is supported by experimental results. By nature, DOC outlet temperature response includes long and time-varying delays. An approximation of the proposed model allows to derive delays analytically, and can be used to schedule control parameters. As a consequence, it is easy to design several standard controllers for the DOC outlet temperature which account for the effects of the inlet temperature (disturbance) and the reductant (control). In this paper, simulation results are presented for a PI, a PID, and a Smith predictor. Interestingly, the three controllers use solely parameters determined from the previous analysis and do not need any extra tuning parameter. The strategies are tested on a standard NEDC driving cycle in simulation. It appears that, among these standard strategies, the DOC partial derivative equations can be efficiently controlled using the presented Smith predictor.
A search for a heavy standard model Higgs boson decaying via H→ZZ→ℓ+ℓ−νν¯, where ℓ=e, μ, is presented. It is based on proton-proton collision data at s=7 TeV, collected by the ATLAS experiment at the LHC in...
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A search for a heavy standard model Higgs boson decaying via H→ZZ→ℓ+ℓ−νν¯, where ℓ=e, μ, is presented. It is based on proton-proton collision data at s=7 TeV, collected by the ATLAS experiment at the LHC in the first half of 2011 and corresponding to an integrated luminosity of 1.04 fb−1. The data are compared to the expected standard model backgrounds. The data and the background expectations are found to be in agreement and upper limits are placed on the Higgs boson production cross section over the entire mass window considered; in particular, the production of a standard model Higgs boson is excluded in the region 340
This Letter presents the first search for supersymmetry in final states containing one isolated electron or muon, jets, and missing transverse momentum from s=7 TeV proton-proton collisions at the LHC. The data were ...
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This Letter presents the first search for supersymmetry in final states containing one isolated electron or muon, jets, and missing transverse momentum from s=7 TeV proton-proton collisions at the LHC. The data were recorded by the ATLAS experiment during 2010 and correspond to a total integrated luminosity of 35 pb−1. No excess above the standard model background expectation is observed. Limits are set on the parameters of the minimal supergravity framework, extending previous limits. Within this framework, for A0=0 GeV, tan β=3, and μ>0 and for equal squark and gluino masses, gluino masses below 700 GeV are excluded at 95% confidence level.
New emerging technologies such as high-precision sensors or new MRI machines drive us towards a challenging quest for new, more effective, and more daring mathematical models and algorithms. Therefore, in the last few...
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The Z→ττ cross section is measured with the ATLAS experiment at the LHC in four different final states determined by the decay modes of the τ leptons: muon-hadron, electron-hadron, electron-muon, and muon-muon. Th...
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The Z→ττ cross section is measured with the ATLAS experiment at the LHC in four different final states determined by the decay modes of the τ leptons: muon-hadron, electron-hadron, electron-muon, and muon-muon. The analysis is based on a data sample corresponding to an integrated luminosity of 36 pb−1, at a proton-proton center-of-mass energy of s=7 TeV. Cross sections are measured separately for each final state in fiducial regions of high detector acceptance, as well as in the full phase space, over the mass region 66–116 GeV. The individual cross sections are combined and the product of the total Z production cross section and Z→ττ branching fraction is measured to be 0.97±0.07(stat)±0.06(syst)±0.03(lumi) nb, in agreement with next-to-next-to-leading order calculations.
This paper describes searches for the pair production of first or second generation scalar leptoquarks using 35 pb−1 of proton-proton collision data recorded by the ATLAS detector at s=7 TeV. Leptoquarks are searche...
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This paper describes searches for the pair production of first or second generation scalar leptoquarks using 35 pb−1 of proton-proton collision data recorded by the ATLAS detector at s=7 TeV. Leptoquarks are searched in events with two oppositely-charged muons or electrons and at least two jets, and in events with one muon or electron, missing transverse momentum and at least two jets. After event selection, the observed yields are consistent with the predicted backgrounds. Leptoquark production is excluded at the 95% CL for masses MLQ<376 (319) GeV and MLQ<422 (362) GeV for first and second generation scalar leptoquarks, respectively, when assuming the branching fraction of a leptoquark to a charged lepton is equal to 1.0 (0.5).
Jets are identified and their properties studied in center-of-mass energy s=7 TeV proton-proton collisions at the Large Hadron Collider using charged particles measured by the ATLAS inner detector. Events are selecte...
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Jets are identified and their properties studied in center-of-mass energy s=7 TeV proton-proton collisions at the Large Hadron Collider using charged particles measured by the ATLAS inner detector. Events are selected using a minimum bias trigger, allowing jets at very low transverse momentum to be observed and their characteristics in the transition to high-momentum fully perturbative jets to be studied. Jets are reconstructed using the anti-kt algorithm applied to charged particles with two radius parameter choices, 0.4 and 0.6. An inclusive charged jet transverse momentum cross section measurement from 4 GeV to 100 GeV is shown for four ranges in rapidity extending to 1.9 and corrected to charged particle-level truth jets. The transverse momenta and longitudinal momentum fractions of charged particles within jets are measured, along with the charged particle multiplicity and the particle density as a function of radial distance from the jet axis. Comparison of the data with the theoretical models implemented in existing tunings of Monte Carlo event generators indicates reasonable overall agreement between data and Monte Carlo. These comparisons are sensitive to Monte Carlo parton showering, hadronization, and soft physics models.
We propose and study a model of molecular motor-induced ordering in a cytoskeletal filament solution for the semidilute case. Motors attach to a pair of filaments and walk along the pair bringing them into closer alig...
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We propose and study a model of molecular motor-induced ordering in a cytoskeletal filament solution for the semidilute case. Motors attach to a pair of filaments and walk along the pair bringing them into closer alignment. In the semidilute regime multiple motors can bind a filament to several others and, for a critical motor density, induce a transition to an ordered phase with a nonzero mean orientation. The motors, on the one hand, cause closer filament alignment, and, on the other hand, induce fluctuations that are dependent on the relative orientation of the filaments to which the motors are attached. We develop a spatially homogenous, mean-field theory that explicitly accounts for a force-dependent detachment rate of motors, which in turn affects the mean and the fluctuations of the net force acting on a filament. This model considers each filament to be in motor contact with all other filaments in the solution. We show that the transition to the oriented state changes from second order to first order when the force-dependent detachment becomes important.
This paper proposes a warm-up strategy for a Diesel Oxidation Catalyst (DOC) which is grounded on a simple distributed parameter model. This first principles model of the propagation of the temperature variations acco...
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This paper proposes a warm-up strategy for a Diesel Oxidation Catalyst (DOC) which is grounded on a simple distributed parameter model. This first principles model of the propagation of the temperature variations accounts for spatially distributed heat generation (due to chemical reactions). We show that heat generation can be regarded as inlet temperature variations. This fact is supported by experimental results. As a consequence, a simple warm-up strategy can be developed. It allows to decrease the DOC response time using pulse input signals. The parameters of the proposed warm-up strategy are exhaustively studied. We show that, to achieve good performance, the strategy need not include more than two pulses and that the pulse magnitude need not be greater than three times the desired final magnitude.
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