C. H. Cheng
A5016466252- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Computational Physics and Python Applications
- Cosmology and Gravitation Theories
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Wildlife Ecology and Conservation
- Nuclear physics research studies
- Rangeland Management and Livestock Ecology
- Astrophysics and Cosmic Phenomena
- Iron-based superconductors research
- Physics of Superconductivity and Magnetism
- Rare-earth and actinide compounds
- Stellar, planetary, and galactic studies
- Scientific Research and Discoveries
- Radiation Detection and Scintillator Technologies
- Opinion Dynamics and Social Influence
- Land Use and Ecosystem Services
Sun Yat-sen University
2017-2024
Chinese Academy of Sciences
2024
Institute of Geographic Sciences and Natural Resources Research
2024
Huaiyin Normal University
2024
Nanjing Agricultural University
2022-2024
Nanjing Institute of Geography and Limnology
2024
South China Normal University
2024
Tsinghua University
2023
Jiangsu University of Science and Technology
2023
Peking University
2019-2023
Based on the full BABAR data sample, we report improved measurements of ratios R(D(*))=B(B[over ¯]→D(*)τ(-)ν[over ¯](τ))/B(B[over ¯]→D(*)ℓ(ℓ)(-)ν[over ¯](ℓ)), where ℓ is either e or μ. These are sensitive to new physics contributions in form a charged Higgs boson. We measure R(D)=0.440±0.058±0.042 and R(D(*))=0.332±0.024±0.018, which exceed standard model expectations by 2.0σ 2.7σ, respectively. Taken together, our results disagree with these at 3.4σ level. This excess cannot be explained...
This work is on the Physics of B Factories. Part A this book contains a brief description SLAC and KEK Factories as well their detectors, BaBar Belle, data taking related issues. discusses tools methods used by experiments in order to obtain results. The results themselves can be found C. Please note that version 3 archive auxiliary book. uses notation alpha, beta, gamma for angles Unitarity Triangle. nominal phi_1, phi_2 phi_3. cite Eur. Phys. J. C74 (2014) 3026.
We search for single-photon events in 53 fb−1 of e+e− collision data collected with the BABAR detector at PEP-II B-Factory. look a single high-energy photon and large missing momentum energy, consistent production spin-1 particle A′ through process e+e−→γA′; A′→invisible. Such particles, referred to as "dark photons," are motivated by theories applying U(1) gauge symmetry dark matter. find no evidence such processes set 90% confidence level upper limits on coupling strength mass range mA′≤8...
Many models of physics beyond the Standard Model predict existence new Abelian forces with gauge bosons mediating interactions between "dark sectors" and Model. We report a search for dark boson Z' coupling only to second third generations leptons in reaction e+e- -> mu+mu- Z', using 514 fb-1 data collected by BABAR experiment. No significant signal is observed masses range 0.212 - 10 GeV. Limits on parameter g' as low 7x10^-4 are derived, leading improvements bounds compared those...
We present a study of the ${D}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$, ${D}^{0}{\ensuremath{\pi}}^{+}$, and ${D}^{*+}{\ensuremath{\pi}}^{\ensuremath{-}}$ systems in inclusive ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}c\overline{c}$ interactions search for new excited $D$ meson states. use data set, consisting $\ensuremath{\sim}454\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, collected at center-of-mass energies near 10.58 GeV by BABAR detector SLAC PEP-II asymmetric-energy...
We report constraints on light dark matter through its interactions with shell electrons in the PandaX-II liquid xenon detector a total $46.9\text{ }\text{ }\mathrm{tonnes}/\mathrm{day}$ exposure. To effectively search for these very low energy electron recoils, ionization-only signals are selected from data. 1821 candidates identified within an ionization signal range between 50 and 75 photoelectrons, corresponding to mean electronic recoil 0.08 0.15 keV. The 90% C.L. exclusion limit...
We report the first dark matter search results using commissioning data from PandaX-4T. Using a time projection chamber with 3.7 tonne of liquid xenon target and an exposure 0.63 tonne·year, 1058 candidate events are identified within approximate nuclear recoil energy window between 5 100 keV. No significant excess over background is observed. Our set stringent limit to matter-nucleon spin-independent interactions, lowest excluded cross section (90% C.L.) 3.8×10^{-47} cm^{2} at mass 40 GeV/c^{2}.
We report a novel search for the cosmic-ray boosted dark matter using 100 tonne·day full dataset of PandaX-II detector located at China Jinping Underground Laboratory. With extra energy gained from cosmic rays, sub-GeV particles can produce visible recoil signals in detector. The diurnal modulations rate and spectrum are utilized to further enhance signal sensitivity. Our result excludes matter-nucleon elastic scattering cross section between 10^{-31} 10^{-28} cm^{2} masses 0.1 MeV/c^{2}...
We report the search results of light dark matter through its interactions with shell electrons and nuclei, using commissioning data from PandaX-4T liquid xenon detector. Low energy events are selected to have an ionization-only signal between 60 200 photoelectrons, corresponding a mean nuclear recoil 0.77 2.54 keV electronic 0.07 0.23 keV. With effective exposure 0.55 tonne$\cdot$year, we set most stringent limits within mass range 40 $\rm{MeV/c^2}$ 10 $\rm{GeV/c^2}$ for point-like...
We report a search on sub-MeV fermionic dark matter absorbed by electrons with an outgoing active neutrino using the 0.63 tonne year exposure collected PandaX-4T liquid xenon experiment. No significant signals are observed over expected background. The data interpreted into limits to effective couplings between such and electron. For axial-vector or vector interactions, our sensitivity is competitive in comparison existing astrophysical bounds decay of candidate photon final states. In...
A search for interactions from solar $^{8}\mathrm{B}$ neutrinos elastically scattering off xenon nuclei using PandaX-4T commissioning data is reported. The energy threshold of this further lowered compared with the previous dark matter, various techniques utilized to suppress background that emerges threshold. blind analysis performed on an effective exposure $0.48\text{ }\text{ }\mathrm{tonne}\text{ }\mathrm{year}$, and no significant excess events observed. Among results obtained...
Xe134 is a candidate isotope for neutrinoless double beta decay (0νββ) search. In addition, the two-neutrino case (2νββ) allowed by standard model of particle physics has not yet been observed. With 656-kg natural xenon in fiducial volume PandaX-4T detector, which contains 10.4% Xe134, and its initial 94.9-day exposure, we have established most stringent constraints on 2νββ 0νββ half-lives, with limits 2.8×1022 yr 3.0×1023 at 90% confidence level, respectively. The limit surpasses previously...
PandaX-4T experiment is a deep-underground dark matter direct search that employs dual-phase time projection chamber with sensitive volume containing 3.7 tonne of liquid xenon. The detector capable simultaneously collecting the primary scintillation and ionization signals, utilizing their ratio to discriminate signals from background sources such as gamma rays beta particles. signal response model plays crucial role in interpreting data obtained by PandaX-4T. It describes conversion...
We report on an improved measurement of the Cabibbo-Kobayashi-Maskawa CP-violating phase γ through a Dalitz plot analysis neutral D meson decays to KS0π+π− and KS0K+K− produced in processes B∓→DK∓, B∓→D*K∓ with D*→Dπ0, Dγ, B∓→DK*∓ K*∓→KS0π∓. Using sample 383×106 BB¯ pairs collected by BABAR detector, we measure γ=(76±22±5±5)° (mod 180°), where first error is statistical, second experimental systematic uncertainty, third reflects uncertainty description distributions. The corresponding...
We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element $|{V}_{\mathrm{cb}}|$ and form-factor slope ${\ensuremath{\rho}}^{2}$ in $\overline{B}\ensuremath{\rightarrow}D{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}$ decays based on $460\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ events recorded at $\ensuremath{\Upsilon}(4S)$ resonance with BABAR detector. are selected which hadronic decay second $B$ meson is fully...
We report e+e−→b¯b cross section measurements by the BABAR experiment performed during an energy scan in range of 10.54 to 11.20 GeV at SLAC PEP-II e+e− collider. A total relative error about 5% is reached more than 300 center-of-mass steps, separated 5 MeV. These can be used derive precise information on parameters Υ(10860) and Υ(11020) resonances. In particular we show that their widths may smaller previously measured.Received 26 September...
The photon spectrum in the inclusive electromagnetic radiative decays of $B$ meson, $B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma}$ plus $B\ensuremath{\rightarrow}{X}_{d}\ensuremath{\gamma}$, is studied using a data sample $(382.8\ifmmode\pm\else\textpm\fi{}4.2)\ifmmode\times\else\texttimes\fi{}{10}^{6}\mathit{\ensuremath{\Upsilon}}(4S)\ensuremath{\rightarrow}B\overline{B}$ collected by BABAR experiment at SLAC. used to extract branching fraction...
We study the processes ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\gamma}$, ${K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}$, and ${K}^{+}{K}^{\ensuremath{-}}{K}^{+}{K}^{\ensuremath{-}}\ensuremath{\gamma}$, where photon is radiated from initial state. About 84 000, 8000, 4200 fully reconstructed events, respectively, are selected $454\text{...
The ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}p\overline{p}$ cross section and the proton magnetic form factor have been measured in center-of-mass energy range from 3.0 to 6.5 GeV using initial-state radiation technique with an undetected photon. This is first measurement of at energies higher than 4.5 GeV. analysis based on $469\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity collected BABAR detector PEP-II collider ${e}^{+}{e}^{\ensuremath{-}}$ near 10.6...
Abstract Aim We explore the phylogeography of Himalayan wolves using multiple genetic markers applied on a landscape‐scale dataset and relate our findings to biogeographic history region. Location Himalayas Nepal, Tibetan Plateau China mountain ranges Central Asia. Taxon wolf (also called wolf), Canis lupus chanco . Methods present large‐scale, non‐invasive study from across their estimated range. analysed 280 scat samples western China, Kyrgyzstan Tajikistan at two mtDNA loci, 17...