A5002542067- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- Advanced Memory and Neural Computing
- stochastic dynamics and bifurcation
- Pharmaceutical studies and practices
- Particle Accelerators and Free-Electron Lasers
- Neural dynamics and brain function
- Medical Coding and Health Information
- Particle Detector Development and Performance
- Nuclear physics research studies
- Immunodeficiency and Autoimmune Disorders
- Atomic and Subatomic Physics Research
University of Science and Technology of China
2024
Southwest University
2023
Shanghai Jiao Tong University
2021
Institute of High Energy Physics
1988-2008
China Center of Advanced Science and Technology
2004
California Institute of Technology
1982-1990
University of Illinois Urbana-Champaign
1987
SLAC National Accelerator Laboratory
1987
Massachusetts Institute of Technology
1982-1984
Brookhaven National Laboratory
1984
We present the general properties of multihadron final states produced by e+e− annihilation at center-of-mass energies from 52 to 57 GeV in AMY detector KEK collider TRISTAN. Global shape, inclusive charged-particle, and particle-flow distributions are presented. Our measurements compared with QCD+fragmentation models that use either leading-logarithmic parton-shower evolution or QCD matrix elements parton level, string cluster fragmentation for hadronization.Received 20 November...
The ratio $R$ of the cross section for ${e}^{+}{e}^{\ensuremath{-}}$ annihilation into hadronic final states to QED muon-pair production is measured be 4.34\ifmmode\pm\else\textpm\fi{}0.45\ifmmode\pm\else\textpm\fi{}0.30 and 4.23\ifmmode\pm\else\textpm\fi{}0.20\ifmmode\pm\else\textpm\fi{}0.21 at c.m. energies 50 52 GeV, respectively. From these values an analysis event shapes we deduce a 95%-confidence-level upper limit rate new heavy charge $+\frac{2}{3}e$ or $\ensuremath{-}\frac{1}{3}e$...
We present evidence for the non-Abelian nature of QCD from a study multijet events produced in ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilations \ensuremath{\surd}s =50 to 57 GeV AMY detector at KEK storage ring TRISTAN. A comparison three-jet event fraction TRISTAN DESY PETRA shows that coupling strength ${\ensuremath{\alpha}}_{s}$ decreases with increasing ${Q}^{2}$. In addition, measurements angular distributions four-jet show triple-gluon vertex.
With a PETRA energy scan in \ensuremath{\le}30-MeV steps, the continuum production of open top quark up to 38.54 GeV is excluded. Over regions from 29.90 38.63 limits are set on product hadronic branching ratio and electronic width ${B}_{h}{\ensuremath{\Gamma}}_{\mathrm{ee}}$ for toponium be less than 2.0 keV at 95% confidence level. By search flavor-changing neutral currents $b$ decay, models without
The measurement of the nonelectromagnetic forward-backward charge asymmetry in reaction e+e−→μ+μ− at s∼34.6 GeV and angular region 0<|cosθ|<0.8 is reported. With a systematic error less than 1%, we observe an (-8.1±2.1)%. This agreement with standard electroweak theory prediction (-7.6±0.6)%. weak-current coupling constants are also reported.Received 30 April 1982DOI:https://doi.org/10.1103/PhysRevLett.48.1701©1982 American Physical Society
We present the charged-particle multiplicity distributions for ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at center-of-mass energies from 50 to 61.4 GeV. The results are based on a data sample corresponding total integrated luminosity of 30 ${\mathrm{pb}}^{\ensuremath{-}1}$ obtained with AMY detector KEK storage ring TRISTAN. deviate significantly modified Poisson and pair distributions, but follow Koba-Nielsen-Olesen scaling well reproduced by LUND parton-shower model.
Three-jet events produced in ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilations are used to provide comparisons between quark and gluon jets. Differences quark-induced gluon-induced jets observed. Quark tend have a more tightly collimated structure than jets, which is reflected the concentration of larger fraction jet's energy near jet axis.
The total cross section for e+e− annihilation into hadrons has been measured CM energies ranging from 50 to 57 GeV. We fit the predictions of standard model these measurements and those at lower energies. mass Z0 boson, MZ, QCD scale parameter, ΛMS, are derived fit. results MZ=88.6−1.8+2.0 GeV/c2, ΛMS=0.15−0.11+0.16
We report mass limits on the ${\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{Z}}^{0}$ and \~{}\fi{}}{W}}^{\ifmmode\pm\else\textpm\fi{}}$, supersymmetric partners of ${Z}^{0}$ ${W}^{\ifmmode\pm\else\textpm\fi{}}$, respectively, using MARK-J detector at PETRA. The experimental signatures in both cases are acoplanar lepton pairs with missing energy. For an additional signature is a single energetic lepton. No evidence found for either \~{}\fi{}}{Z}}^{0}({M}_{{\stackrel{\ifmmode...
We have searched for resonances in the reaction ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons}, \ensuremath{\gamma}\ensuremath{\gamma}, \ensuremath{\mu}\ensuremath{\mu}, \mathrm{and} \mathrm{ee}$, energy range $39.79<\sqrt{s}<45.52$ GeV, using Mark J detector at PETRA. obtain stringent upper limits on production of toponium and particles postulated to explain ${Z}^{0}\ensuremath{\rightarrow}\mathrm{lepton}\mathrm{pair}+\ensuremath{\gamma}$ events observed CERN...
Multihadronic ${e}^{+}{e}^{\ensuremath{-}}$ annihilation events containing final-state leptons have been investigated with a 4.7-${\mathrm{pb}}^{\ensuremath{-}1}$ data sample at c.m. energies of 50 and 52 GeV. The number low-thrust ($T\ensuremath{\le}0.8$) isolated is consistent the expectation standard model five quark flavors. Limits on production new quarks are reported.
The ratio $R$ of the total cross section for ${e}^{+}{e}^{\ensuremath{-}}$ annihilation into hadrons to lowest-order QED ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ has been measured center-of-mass energies ranging from 50 61.4 GeV. If we allow an overall shift ---4.9%, about 1.5 times our estimated normalization error, results are consistent with standard-model predictions.
By studying ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilations in the center-of-mass energy range between 50 and 60.8 GeV, we have established a 95%-confidence-level lower limit on mass of fourth-generation charge -(1/3 quark b' 27.2 GeV. In contrast with all previous searches, this has been obtained through consideration decay processes b'\ensuremath{\rightarrow}b\ensuremath{\gamma} b'\ensuremath{\rightarrow}bg aswell as...
Using 123 multihadronic inclusive muon-production ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilation events at an average c.m. energy of 55.2 GeV, we extracted the forward-backward charge asymmetry ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$\ensuremath{\rightarrow}bb\ifmmode\bar\else\textasciimacron\fi{} process and R ratio for bb\ifmmode\bar\else\textasciimacron\fi{} production. We used analysis method in which behavior c quark lighter quarks is assumed, with only that b left indeterminate....
The forward-backward asymmetry of quarks produced in ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilations, summed over all flavors, is measured at \ensuremath{\surd}s between 50 and 60.8 GeV. Methods determining the charge direction jet pairs are discussed. found to agree with five-flavor standard model.
A search for pair production of fourth-generation sequential leptons in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at a center-of-mass energy $\sqrt{s}=56$ GeV is reported. Event topologies corresponding to the cases where one particle decays leptonically while other hadronically as well those both particles decay were explored. We set 95%-confidence-level lower limit 27.6 GeV/${\mathit{c}}^{2}$ mass lepton.
A search for unstable heavy neutral leptons has been made at center-of-mass energies from 50 to 60.8 GeV with the AMY detector KEK Storage ring TRISTAN. The are assumed decay via mixing electrons and muons. Events two were searched for. No evidence their existence was found. Limits in mass range \ensuremath{\le}28.1 GeV/${c}^{2}$ mixing-parameter...
The decay \ensuremath{\tau}\ensuremath{\rightarrow}\ensuremath{\rho}\ensuremath{\nu} is studied in \ensuremath{\tau} pair production by ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilation at \ensuremath{\surd}s =3.77 GeV, 0.20 GeV above \ensuremath{\tau}\ensuremath{\tau} threshold. branching fraction measured to be B(\ensuremath{\tau}\ensuremath{\rightarrow}\ensuremath{\rho}\ensuremath{\nu})=(23.0\ifmmode\pm\else\textpm\fi{}1.3\ifmmode\pm\else\textpm\fi{}1.7)%. distribution of the helicity...