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Author

Jie Zhang

Other affiliations: University of Bedfordshire, CERN, Xidian University  ...read more
Bio: Jie Zhang is an academic researcher from East China University of Science and Technology. The author has contributed to research in topics: Medicine & Large Hadron Collider. The author has an hindex of 178, co-authored 4857 publications receiving 221720 citations. Previous affiliations of Jie Zhang include University of Bedfordshire & CERN.


Papers
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Georges Aad1, Brad Abbott2, Jalal Abdallah3, Ovsat Abdinov4  +2847 moreInstitutions (207)
TL;DR: In this paper, a detailed study of techniques for identifying boosted, hadronically decaying W bosons using 20.3 fb −¹ of proton-proton collision data collected by the ATLAS detector at the LHC at a center-of-mass energy √s = 8 TeV.
Abstract: This paper reports a detailed study of techniques for identifying boosted, hadronically decaying W bosons using 20.3 fb −¹ of proton–proton collision data collected by the ATLAS detector at the LHC at a centre-of-mass energy √s = 8 TeV. A range of techniques for optimising the signal jet mass resolution are combined with various jet substructure variables. The results of these studies in Monte Carlo simulations show that a simple pairwise combination of groomed jet mass and one substructure variable can provide a 50 % efficiency for identifying W bosons with transverse momenta larger than 200 GeV while maintaining multijet background efficiencies of 2–4 % for jets with the same transverse momentum. These signal and background efficiencies are confirmed in data for a selection of tagging techniques.

78 citations

Journal ArticleDOI
Georges Aad1, Georges Aad2, E. Abat3, Brad Abbott4  +3253 moreInstitutions (185)
TL;DR: In this paper, the performance of the ATLAS detector in the first half a million minimum bias events of the LHC collision data was investigated at center-of-mass energies of 0.9 TeV and 2.36 TeV.
Abstract: More than half a million minimum-bias events of LHC collision data were collected by the ATLAS experiment in December 2009 at centre-of-mass energies of 0.9 TeV and 2.36 TeV. This paper reports on studies of the initial performance of the ATLAS detector from these data. Comparisons between data and Monte Carlo predictions are shown for distributions of several track- and calorimeter-based quantities. The good performance of the ATLAS detector in these first data gives confidence for successful running at higher energies.

78 citations

Journal ArticleDOI
TL;DR: In this paper, the lifetime and width of the Higgs boson were obtained from H to ZZ to 4 lepton events using data recorded by the CMS experiment during the LHC run 1 with an integrated luminosity of 5.1 and 19.7 inverse femtobarns at a center-of-mass energy of 7 and 8 TeV, respectively.
Abstract: Constraints on the lifetime and width of the Higgs boson are obtained from H to ZZ to 4 lepton events using data recorded by the CMS experiment during the LHC run 1 with an integrated luminosity of 5.1 and 19.7 inverse femtobarns at a center-of-mass energy of 7 and 8 TeV, respectively. The measurement of the Higgs boson lifetime is derived from its flight distance in the CMS detector with an upper bound of tau[H] 3.5E-9 MeV. The measurement of the width is obtained from an off-shell production technique, generalized to include anomalous couplings of the Higgs boson to two electroweak bosons. From this measurement, a joint constraint is set on the Higgs boson width and a parameter f[LQ] that expresses an anomalous coupling contribution as an on-shell cross-section fraction. The limit on the Higgs boson width is Gamma[H] < 46 MeV with f[LQ] unconstrained and Gamma[H] < 26 MeV for f[LQ] = 0 at the 95% CL. The constraint f[LQ] < 3.8E-3 at the 95% CL is obtained for the expected standard model Higgs boson width.

78 citations

Journal ArticleDOI
TL;DR: In this article, a photo-Fenton composite was designed and synthesized as a photonic crystal with a hierarchical macro-mesoporous structure, which possesses a slow-light-effect region that overlaps with the absorption spectrum of methyl orange (MO).
Abstract: In this work, the Fe2O3-SiO2 composite photo-Fenton catalyst was designed and synthesized as a photonic crystal with a hierarchical macro-mesoporous structure, which possesses a slow-light-effect region that overlaps with the absorption spectrum of methyl orange (MO). The prepared material exhibits remarkably high and stable photo-Fenton catalytic performance for the degradation of MO using only a low concentration of H2O2 under visible light irradiation. The catalytic activity of the as-prepared material is better than that of the corresponding macroporous or mesoporous Fe2O3-SiO2 composites as well as commercial Fe2O3 or the homogenous photo-Fenton system of FeCl3 · 6H2O. The efficient use of H2O2 and the high catalytic activity are attributed to (i) the excellent adsorption of MO by the hierarchical macro-mesoporous structure and (ii) enhanced light harvesting from coupling the absorption spectrum of MO with the slow-light-effect region of the photonic crystal. This hierarchical macro-mesoporous Fe2O3-SiO2 photonic crystal is expected to be a promising cost-effective photo-Fenton catalyst for degradation of a variety of dyes by deliberately tuning its slow-light-effect region, and opens up new perspectives for the development of highly efficient photo-Fenton catalysts for environmental remediation technology.

78 citations

Journal ArticleDOI
Georges Aad1, Brad Abbott2, J. Abdallah3, A. A. Abdelalim4  +3049 moreInstitutions (193)
TL;DR: No excess of events is observed above the expected background and limits on the Higgs boson production times branching ratio to weakly interacting, long-lived particles are derived as a function of the particle proper decay length.
Abstract: A search for the decay of a light Higgs boson (120-140 GeV) to a pair of weakly interacting, long-lived particles in 1.94 fb(-1) of proton-proton collisions at root s = 7 TeV recorded in 2011 by the ATLAS detector is presented. The search strategy requires that both long-lived particles decay inside the muon spectrometer. No excess of events is observed above the expected background and limits on the Higgs boson production times branching ratio to weakly interacting, long-lived particles are derived as a function of the particle proper decay length.

78 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Journal ArticleDOI
TL;DR: This study enters into the particular topics of the relative quantification in real-time RT-PCR of a target gene transcript in comparison to a reference gene transcript and presents a new mathematical model that needs no calibration curve.
Abstract: Use of the real-time polymerase chain reaction (PCR) to amplify cDNA products reverse transcribed from mRNA is on the way to becoming a routine tool in molecular biology to study low abundance gene expression. Real-time PCR is easy to perform, provides the necessary accuracy and produces reliable as well as rapid quantification results. But accurate quantification of nucleic acids requires a reproducible methodology and an adequate mathematical model for data analysis. This study enters into the particular topics of the relative quantification in real-time RT–PCR of a target gene transcript in comparison to a reference gene transcript. Therefore, a new mathematical model is presented. The relative expression ratio is calculated only from the real-time PCR efficiencies and the crossing point deviation of an unknown sample versus a control. This model needs no calibration curve. Control levels were included in the model to standardise each reaction run with respect to RNA integrity, sample loading and inter-PCR variations. High accuracy and reproducibility (<2.5% variation) were reached in LightCycler PCR using the established mathematical model.

30,462 citations

Journal ArticleDOI
Claude Amsler1, Michael Doser2, Mario Antonelli, D. M. Asner3  +173 moreInstitutions (86)
TL;DR: This biennial Review summarizes much of particle physics, using data from previous editions.

12,798 citations