Jie Zhang

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.

Measurement of Z Boson Production in Pb-Pb Collisions at root s(NN)=2.76 TeV with the ATLAS Detector

Abstract: The ATLAS experiment has observed 1995 Z boson candidates in data corresponding to 0.15 nb(-1) of integrated luminosity obtained in the 2011 LHC Pb + Pb run at root s(NN) = 2.76 TeV. The Z bosons are reconstructed via dielectron and dimuon decay channels, with a background contamination of less than 3%. Results from the two channels are consistent and are combined. Within the statistical and systematic uncertainties, the per-event Z boson yield is proportional to the number of binary collisions estimated by the Glauber model. The elliptic anisotropy of the azimuthal distribution of the Z boson with respect to the event plane is found to be consistent with zero. DOI: 10.1103/PhysRevLett.110.022301

Study ofe+e−→ΛΛ¯,ΛΣ¯0,Σ0Σ¯0using initial state radiation withBABAR

Abstract: We study the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathit{\ensuremath{\Lambda}}\overline{\mathit{\ensuremath{\Lambda}}}\ensuremath{\gamma}$, $\mathit{\ensuremath{\Lambda}}{\overline{\mathit{\ensuremath{\Sigma}}}}^{0}\ensuremath{\gamma}$, ${\mathit{\ensuremath{\Sigma}}}^{0}{\overline{\mathit{\ensuremath{\Sigma}}}}^{0}\ensuremath{\gamma}$ processes using $230\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity collected by the BABAR detector at ${e}^{+}{e}^{\ensuremath{-}}$ center-of-mass energy of 10.58 GeV. From the analysis of the baryon-antibaryon mass spectra the cross sections for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathit{\ensuremath{\Lambda}}\overline{\mathit{\ensuremath{\Lambda}}}$, $\mathit{\ensuremath{\Lambda}}{\overline{\mathit{\ensuremath{\Sigma}}}}^{0}$, ${\mathit{\ensuremath{\Sigma}}}^{0}{\overline{\mathit{\ensuremath{\Sigma}}}}^{0}$ are measured in the dibaryon mass range from threshold up to $3\text{ }\text{ }\mathrm{GeV}/{c}^{2}$. The ratio of electric and magnetic form factors, $|{G}_{E}/{G}_{M}|$, is measured for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathit{\ensuremath{\Lambda}}\overline{\mathit{\ensuremath{\Lambda}}}$, and limits on the relative phase between $\mathit{\ensuremath{\Lambda}}$ form factors are obtained. We also measure the $J/\ensuremath{\psi}\ensuremath{\rightarrow}\mathit{\ensuremath{\Lambda}}\overline{\mathit{\ensuremath{\Lambda}}}$, ${\mathit{\ensuremath{\Sigma}}}^{0}{\overline{\mathit{\ensuremath{\Sigma}}}}^{0}$, and $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\mathit{\ensuremath{\Lambda}}\overline{\mathit{\ensuremath{\Lambda}}}$ branching fractions.

Study of the exclusive initial-state-radiation production of the DD̄ system

Abstract: A study of exclusive production of the D{bar D} system through initial-state radiation is performed in a search for charmonium states, where D = D{sup 0} or D{sup +}. The D{sup 0} mesons are reconstructed in the D{sup 0} {yields} K{sup -}{pi}{sup +}, D{sup 0} {yields} K{sup -}{pi}{sup +}{pi}{sup 0}, and D{sup 0} {yields} K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -} decay modes. The D{sup +} is reconstructed through the D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +} decay mode. The analysis makes use of an integrated luminosity of 288.5 fb{sup -1} collected by the BABAR experiment. The D{bar D} mass spectrum shows a clear {psi}(3770) signal. Further structures appear in the 3.9 and 4.1 GeV/c{sup 2} regions. No evidence is found for Y(4260) decays to D{bar D}, implying an upper limit {Beta}(Y(4260) {yields} D{bar D})/{Beta}(Y(4260) {yields} J/{psi}{pi}{sup +}{pi}{sup -}) < 7.6 (95% confidence level).

Search for photonic signatures of gauge-mediated supersymmetry in 8 TeV pp collisions with the ATLAS detector

Abstract: A search is presented for photonic signatures motivated by generalized models of gauge-mediated supersymmetry breaking. This search makes use of 20.3 fb(-1) of proton-proton collision data at root s = 8 TeV recorded by the ATLAS detector at the LHC, and explores models dominated by both strong and electroweak production of supersymmetric partner states. Four experimental signatures incorporating an isolated photon and significant missing transverse momentum are explored. These signatures include events with an additional photon, lepton, b-quark jet, or jet activity not associated with any specific underlying quark flavor. No significant excess of events is observed above the Standard Model prediction and model-dependent 95% confidence-level exclusion limits are set.

I and i

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 …

A new mathematical model for relative quantification in real-time RT-PCR.

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.