In this paper, we propose a design of far-field single speaker localization system including noisy speech separation and enhancement with two separated channel microphones. First, we perform noisy speech separation si...
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This work treats the problem of joint estimation of time-delay and spatial (direction-of-arrival, DOA) parameters of several replicas of a known signal in an unknown spatially correlated field. Unstructured and struct...
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This work treats the problem of joint estimation of time-delay and spatial (direction-of-arrival, DOA) parameters of several replicas of a known signal in an unknown spatially correlated field. Unstructured and structured data models have been proposed for maximum likelihood (ML) estimators, whereas the former suffers from a severe performance degradation in some scenarios, and the latter involves huge complexity. In this work it is shown how the extended invariance principle (EXIP) can be applied to obtain estimates with the quality of those of the structured model, but with much lower complexity than directly utilizing the structured model. We present how to improve the quality of the time-delay estimates obtained with an unstructured spatial model by introducing DOA estimates. DOA estimates are derived either directly applying EXIP with a polynomial rooting approach or with decoupled estimators for temporal and spatial parameters applying Unitary ESPRIT. Both methods are compared with respect to estimation accuracy and complexity. Exemplarily, simulation results for time-delay estimation for GPS (Global Positioning System) are shown and confirm that our proposals both approach the Cramer-Rao lower bound (CRLB) of the structured model.
The production of KS0 and Λ hadrons is studied in pp collision data at s=0.9 and 7 TeV collected with the ATLAS detector at the LHC using a minimum-bias trigger. The observed distributions of transverse momentum, rap...
The production of KS0 and Λ hadrons is studied in pp collision data at s=0.9 and 7 TeV collected with the ATLAS detector at the LHC using a minimum-bias trigger. The observed distributions of transverse momentum, rapidity, and multiplicity are corrected to hadron level in a model-independent way within well-defined phase-space regions. The distribution of the production ratio of Λ¯ to Λ baryons is also measured. The results are compared with various Monte Carlo simulation models. Although most of these models agree with data to within 15% in the KS0 distributions, substantial disagreements are found in the Λ distributions of transverse momentum.
Inclusive jet and dijet cross sections have been measured in proton-proton collisions at a center-of-mass energy of 7 TeV using the ATLAS detector at the Large Hadron Collider. The cross sections were measured using j...
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Inclusive jet and dijet cross sections have been measured in proton-proton collisions at a center-of-mass energy of 7 TeV using the ATLAS detector at the Large Hadron Collider. The cross sections were measured using jets clustered with the anti-kt algorithm with parameters R=0.4 and R=0.6. These measurements are based on the 2010 data sample, consisting of a total integrated luminosity of 37 pb−1. Inclusive jet double-differential cross sections are presented as a function of jet transverse momentum, in bins of jet rapidity. Dijet double-differential cross sections are studied as a function of the dijet invariant mass, in bins of half the rapidity separation of the two leading jets. The measurements are performed in the jet rapidity range |y|<4.4, covering jet transverse momenta from 20 GeV to 1.5 TeV and dijet invariant masses from 70 GeV to 5 TeV. The data are compared to expectations based on next-to-leading-order QCD calculations corrected for nonperturbative effects, as well as to next-to-leading-order Monte Carlo predictions. In addition to a test of the theory in a new kinematic regime, the data also provide sensitivity to parton distribution functions in a region where they are currently not well-constrained.
Results are presented on the production of jets of particles in association with a Z/γ* boson, in proton-proton collisions at s=7 TeV with the ATLAS detector. The analysis includes the full 2010 data set, collected ...
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Results are presented on the production of jets of particles in association with a Z/γ* boson, in proton-proton collisions at s=7 TeV with the ATLAS detector. The analysis includes the full 2010 data set, collected with a low rate of multiple proton-proton collisions in the accelerator, corresponding to an integrated luminosity of 36 pb−1. Inclusive jet cross sections in Z/γ* events, with Z/γ* decaying into electron or muon pairs, are measured for jets with transverse momentum pT>30 GeV and jet rapidity |y|<4.4. The measurements are compared to next-to-leading-order perturbative QCD calculations, and to predictions from different Monte Carlo generators implementing leading-order matrix elements supplemented by parton showers.
This paper describes a measurement of the W boson transverse momentum distribution using ATLAS pp collision data from the 2010 run of the LHC at s=7 TeV, corresponding to an integrated luminosity of about 31 pb−1. E...
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This paper describes a measurement of the W boson transverse momentum distribution using ATLAS pp collision data from the 2010 run of the LHC at s=7 TeV, corresponding to an integrated luminosity of about 31 pb−1. Events form both W→eν and W→μν are used, and the transverse momentum of the W candidates is measured through the energy deposition in the calorimeter from the recoil of the W. The resulting distributions are unfolded to obtain the normalized differential cross sections as a function of the W boson transverse momentum. We present results for pTW<300 GeV in the electron and muon channels as well as for their combination, and compare the combined results to the predictions of perturbative QCD and a selection of event generators.
We present an update of a search for supersymmetry in final states containing jets, missing transverse momentum, and one isolated electron or muon, using 1.04 fb−1 of proton-proton collision data at s=7 TeV recorded...
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We present an update of a search for supersymmetry in final states containing jets, missing transverse momentum, and one isolated electron or muon, using 1.04 fb−1 of proton-proton collision data at s=7 TeV recorded by the ATLAS experiment at the LHC in the first half of 2011. The analysis is carried out in four distinct signal regions with either three or four jets and variations on the (missing) transverse momentum cuts, resulting in optimized limits for various supersymmetry models. No excess above the standard model background expectation is observed. Limits are set on the visible cross section of new physics within the kinematic requirements of the search. The results are interpreted as limits on the parameters of the minimal supergravity framework, limits on cross sections of simplified models with specific squark and gluino decay modes, and limits on parameters of a model with bilinear R-parity violation.
An inclusive search for anomalous production of two prompt, isolated muons with the same electric charge is presented. The search is performed in a data sample corresponding to 1.6 fb−1 of integrated luminosity colle...
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An inclusive search for anomalous production of two prompt, isolated muons with the same electric charge is presented. The search is performed in a data sample corresponding to 1.6 fb−1 of integrated luminosity collected in 2011 at s=7 TeV with the ATLAS detector at the LHC. Muon pairs are selected by requiring two isolated muons of the same electric charge with pT>20 GeV and |η|<2.5. Minimal requirements are placed on the rest of the event activity. The distribution of the invariant mass of the muon pair m(μμ) is found to agree well with the background expectation. Upper limits on the cross section for anomalous production of two muons with the same electric charge are placed as a function of m(μμ) within a fiducial region defined by the event selection. The fiducial cross-section limit constrains the like-sign top-quark pair-production cross section to be below 3.7 pb at 95% confidence level. The data are also analyzed to search for a narrow like-sign dimuon resonance as predicted for e.g. doubly charged Higgs bosons (H±±). Assuming pair production of H±± bosons and a branching ratio to muons of 100% (33%), this analysis excludes masses below 355 (244) GeV and 251 (209) GeV for H±± bosons coupling to left-handed and right-handed fermions, respectively.
This paper presents a study of the possible ordering of charged hadrons in the azimuthal angle relative to the beam axis in high-energy proton-proton collisions at the Large Hadron Collider (LHC). A spectral analysis ...
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This paper presents a study of the possible ordering of charged hadrons in the azimuthal angle relative to the beam axis in high-energy proton-proton collisions at the Large Hadron Collider (LHC). A spectral analysis of correlations between longitudinal and transverse components of the momentum of the charged hadrons, driven by the search for phenomena related to the structure of the QCD field, is performed. Data were recorded with the ATLAS detector at center-of-mass energies of s=900 GeV and s=7 TeV. The correlations measured in a kinematic region dominated by low-pT particles are not well described by conventional models of hadron production. The measured spectra show features consistent with the fragmentation of a QCD string represented by a helixlike ordered gluon chain.
We report a study of final states containing a W boson and hadronic jets, produced in proton-proton collisions at a center-of-mass energy of 7 TeV. The data were collected with the ATLAS detector at the CERN LHC and c...
We report a study of final states containing a W boson and hadronic jets, produced in proton-proton collisions at a center-of-mass energy of 7 TeV. The data were collected with the ATLAS detector at the CERN LHC and comprise the full 2010 data sample of 36 pb−1. Cross sections are determined using both the electron and muon decay modes of the W boson and are presented as a function of inclusive jet multiplicity, Njet, for up to five jets. At each multiplicity, cross sections are presented as a function of jet transverse momentum, the scalar sum of the transverse momenta of the charged lepton, missing transverse momentum, and all jets, the invariant mass spectra of jets, and the rapidity distributions of various combinations of leptons and final-state jets. The results, corrected for all detector effects and for all backgrounds such as diboson and top quark pair production, are compared with particle-level predictions from perturbative QCD. Leading-order multiparton event generators, normalized to the next-to-next-to-leading-order total cross section for inclusive W-boson production, describe the data reasonably well for all measured inclusive jet multiplicities. Next-to-leading-order calculations from MCFM, studied here for Njet≤2, and BlackHat-Sherpa, studied here for Njet≤4, are found to be mostly in good agreement with the data.
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