Showing papers by "Zhengguo Zhao published in 2008"
Posted Content•
TL;DR: In this article, a detailed study of the expected performance of the ATLAS detector is presented, together with the reconstruction of tracks, leptons, photons, missing energy and jets, along with the performance of b-tagging and the trigger.
Abstract: A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN.
1,160 citations
11 Apr 2008-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the authors report on the design, deployment and performance of a dedicated drift tube mini-chamber conceived for continuous monitoring and drift time calibration of the ATLAS MDT operating gas.
Abstract: The ATLAS Muon Spectrometer incorporates 354 000 drift tubes assembled into 1200 Monitored Drift Tube (MDT) precision chambers, with a total gas volume of 723 m 3 . This MDT gas, Ar 93% and CO 2 7% at 3 bar, is cycled through the spectrometer at a rate of one total detector volume per day. Achieving the 80 μ m drift tube design resolution requires stringent gas quality control as a fundamental component of the MDT calibration program. We report on the design, deployment and performance of a dedicated MDT mini-chamber conceived for continuous monitoring and drift time calibration of the ATLAS MDT operating gas. This chamber enables measurement of the drift spectra from which gas properties relevant to MDT calibrations and stable operating conditions are determined. Located in the ATLAS gas facility at CERN, the mini-chamber produces hourly drift spectra which are automatically analyzed. Results are published online and disseminated to the ATLAS muon system conditions and calibration databases in real time.
10 citations
TL;DR: In this article, an event reweighting technique incorporated in multivariate training algorithms has been developed and tested with Artificial Neural Networks (ANN) and Boosted Decision Trees (BDT).
Abstract: An event reweighting technique incorporated in multivariate training algorithms has been developed and tested with Artificial Neural Networks (ANN) and Boosted Decision Trees (BDT). The performance of the ANNs and BDTs resulting from this event reweighting training is compared to the performance from conventional equal event weighting training. The comparison is performed in the context of physics analysis in the ATLAS experiment at the Large Hadron Collider (LHC), which will explore the fundamental nature of matter and the basic forces that shape our universe. We demonstrate that the event reweighting technique provides an unbiased method of multivariate training for event pattern recognition.
01 Mar 2008
TL;DR: In this article, the authors performed a study of diboson production in pp collisions at center of mass energy of 14 TeV, predicted by the Standard Model electroweak interactions, with the ATLAS detector.
Abstract: Studies of diboson production in pp collisions at center of mass energy of 14 TeV, predicted by the Standard Model electroweak interactions, will be performed with the ATLAS detector. Signals of the WW, ZW, ZZ, Wγ, Zγ channels are searched through their multi-lepton/photon final states while the sources of background are also studied. On this basis, lepton identification and selection efficiencies are optimized using events of Z decays to two leptons and the missing energy resolution and its systematic errors are studied via W boson decays to lepton and neutrino. Analysis with advanced techniques such as Boosted Decision Trees are applied for the WW, WZ and W / Z γ signals. Finally, the cross section measurements systematic and statistical uncertainties are estimated with respect to integrated luminosity of 0.1 to 10 f b −1 . The method of extracting anomalous triple-gauge coupling measurement is also presented.