J. F. Chang
A5101976170- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Neutrino Physics Research
- Computational Physics and Python Applications
- Medical Imaging Techniques and Applications
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Astrophysics and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- Crystallography and Radiation Phenomena
- Noncommutative and Quantum Gravity Theories
- Advanced NMR Techniques and Applications
- Cosmology and Gravitation Theories
Institute of High Energy Physics
2013-2024
Chinese Academy of Sciences
2022-2024
Paul Scherrer Institute
2023
The electromagnetic process $e^{+}e^{-}\to p\bar{p}$ is studied with the initial-state-radiation technique using 7.5 fb$^{-1}$ of data collected by BESIII experiment at seven energy points from 3.773 to 4.600 GeV. Born cross section and effective form factor proton are measured production threshold 3.0 GeV/$c^{2}$ $p\bar{p}$ invariant-mass spectrum. ratio electric magnetic factors determined analysis proton-helicity angular distribution.
Recently, the LHAASO Collaboration published detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with highest energy photon reaching 1.4 PeV. The first PeV γ rays from astrophysical may provide a very sensitive probe effect Lorentz invariance violation (LIV), which results in decay high-energy superluminal scenario and hence sharp cutoff spectrum. Two are studied this work. No signature existence LIV is found their spectra, lower limits on scale derived. Our show that first-order...
The process e^{+}e^{-}→D_{s}^{*+}D_{s}^{*-} is studied with a semi-inclusive method using data samples at center-of-mass energies from threshold to 4.95 GeV collected the BESIII detector operating Beijing Electron Positron Collider. Born cross sections of are measured for first time high precision in this energy region. Two resonance structures observed energy-dependent around 4.2 and 4.4 GeV. By fitting coherent sum three Breit-Wigner amplitudes one phase-space amplitude, two significant...
Based on a data sample of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mo stretchy="false">(</a:mo><a:mn>2712.4</a:mn><a:mo>±</a:mo><a:mn>14.3</a:mn><a:mo stretchy="false">)</a:mo><a:mo>×</a:mo><a:msup><a:mn>10</a:mn><a:mn>6</a:mn></a:msup><a:mi>ψ</a:mi><a:mo stretchy="false">(</a:mo><a:mn>3686</a:mn><a:mo stretchy="false">)</a:mo></a:math> events collected with the BESIII detector at BEPCII collider, M1 transition <g:math...
We study the decays of $J/\psi$ and $\psi(3686)$ to final states $\Sigma(1385)^{0}\bar\Sigma(1385)^{0}$ $\Xi^0\bar\Xi^{0}$ based on a single baryon tag method using data samples $(1310.6 \pm 7.0) \times 10^{6}$ $(447.9 2.9) events collected with BESIII detector at BEPCII collider. The are observed for first time. measured branching fractions $\psi(3686)\rightarrow\Xi^0\bar\Xi^{0}$ in good agreement with, much more precise, than previously published results. angular parameters these also...
Using e^{+}e^{-} annihilation data of 2.93 fb^{-1} collected at center-of-mass energy sqrt[s]=3.773 GeV with the BESIII detector, we measure absolute branching fraction D^{0}→K^{-}μ^{+}ν_{μ} significantly improved precision: B_{D^{0}→K^{-}μ^{+}ν_{μ}}=(3.413±0.019_{stat}±0.035_{syst})%. Combining our previous measurement B_{D^{0}→K^{-}e^{+}ν_{e}}, ratio two fractions is determined to be B_{D^{0}→K^{-}μ^{+}ν_{μ}}/B_{D^{0}→K^{-}e^{+}ν_{e}}=0.974±0.007_{stat}±0.012_{syst}, which agrees...
The cross sections of the process $e^{+}e^{-} \to \eta J/\psi$ at center-of-mass energies ($\sqrt{s}$) between 3.81 and 4.60 GeV are measured with high precision by using data samples collected BESIII detector operating BEPCII storage ring. Three structures observed analyzing lineshape sections, a maximum-likelihood fit including three resonances is performed assuming lowest lying structure $\psi(4040)$. For other resonances, we obtain masses $(4218.7 \pm 4.0 2.5)$ $(4380.4 14.2 1.8)$...
The study of the Cabibbo-favored semileptonic decay Λ_{c}^{+}→Λe^{+}ν_{e} is reported using a 4.5 fb^{-1} data sample e^{+}e^{-} annihilations collected at center-of-mass energies ranging from 4.600 GeV to 4.699 with BESIII detector BEPCII collider. branching fraction measured be B(Λ_{c}^{+}→Λe^{+}ν_{e})=(3.56±0.11_{stat}±0.07_{syst})%, which most precise measurement date. Furthermore, we perform an investigation internal dynamics in Λ_{c}^{+}→Λe^{+}ν_{e}. We provide first direct comparisons...
We present an analysis of the process $\psi(3686) \to \Omega^- \bar{\Omega}^+$ ($\Omega^-\to K^-\Lambda$, $\bar{\Omega}^+\to K^+\bar{\Lambda}$, $\Lambda\to p\pi^-$, $\bar{\Lambda}\to \bar{p}\pi^+$) based on a data set $448\times 10^6$ $\psi(3686)$ decays collected with BESIII detector at BEPCII electron-positron collider. The helicity amplitudes for and decay parameters subsequent $\Omega^-\to K^-\Lambda$ $(\bar{\Omega}^+\to K^+\bar{\Lambda})$ are measured first time by fit to angular...
Using <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mn>7.9</a:mn><a:mrow><a:mi mathvariant="normal">f</a:mi><a:msup><a:mi mathvariant="normal">b</a:mi><a:mrow><a:mo>−</a:mo><a:mn>1</a:mn></a:mrow></a:msup></a:mrow></a:math> of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msup><e:mi>e</e:mi><e:mo>+</e:mo></e:msup><e:msup><e:mi>e</e:mi><e:mo>−</e:mo></e:msup></e:math> collision data collected at <g:math...
Using a data sample corresponding to an integrated luminosity of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mn>10.9</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:msup><a:mrow><a:mi>fb</a:mi></a:mrow><a:mrow><a:mo>−</a:mo><a:mn>1</a:mn></a:mrow></a:msup></a:mrow></a:math> collected at center-of-mass energies from 4.16 4.34 GeV with the BESIII detector, we search for decay <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"...
We report the observation and study of decay $J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\phi}\ensuremath{\eta}{\ensuremath{\eta}}^{\ensuremath{'}}$ using $1.3\ifmmode\times\else\texttimes\fi{}1{0}^{9}$ $J/\ensuremath{\psi}$ events collected with BESIII detector. Its branching fraction, including all possible intermediate states, is measured to be $(2.32\ifmmode\pm\else\textpm\fi{}0.06\ifmmode\pm\else\textpm\fi{}0.16)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. also...
We investigate the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}K\overline{K}J/\ensuremath{\psi}$ at center-of-mass energies from 4.189 to 4.600 GeV using $4.7\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data collected by BESIII detector BEPCII collider. The Born cross sections for reactions ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}J/\ensuremath{\psi}$ and ${K}_{S}^{0}{K}_{S}^{0}J/\ensuremath{\psi}$ are measured as a function...
A search for a massless dark photon ${\ensuremath{\gamma}}^{\ensuremath{'}}$ is conducted using $4.5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collision data collected at center-of-mass energies between 4.600 and 4.699 GeV with the BESIII detector BEPCII. No significant signal observed, upper limit on branching fraction $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{\ensuremath{\gamma}}^{\ensuremath{'}})$ determined to be...
Using a sample of $(225.3\pm 2.8)\times 10^{6}$ $J/\psi$ decays collected with the BESIII detector at BEPCII, searches for invisible $\eta$ and $\eta^\prime$ in $J/\psi\to\phi\eta$ $\phi\eta^\prime$ are performed. Decays $\phi \to K^{+}K^{-}$ used to tag decays. No signals above background found decays, upper limits 90% confidence level determined be $2.58\times10^{-4}$ ratio $\frac{\mathcal{B}(\eta\to\rm{invisible})}{\mathcal{B}(\eta\to\gamma\gamma)}$ $2.39\times10^{-2}$...
A search for the charged lepton flavor violating decay $J/\psi\to e^{\pm}\tau^{\mp}$ with $\tau^{\mp} \to \pi^{\mp}\pi^0\nu_{\tau}$ is performed about $10$ billion $J/ \psi$ events collected BESIII detector at BEPCII. No significant signal observed, and an upper limit set on branching fraction $\mathcal{B}(J/\psi\to e^{\pm}\tau^{\mp})<7.5\times10^{-8}$ 90$\%$ confidence level. This improves previously published by two orders of magnitude.
The study of the Cabibbo-favored semileptonic decay ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}{\ensuremath{\mu}}^{+}{\ensuremath{\nu}}_{\ensuremath{\mu}}$ is reported using $4.5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data collected at center-of-mass energies ranging from 4.600 to 4.699 GeV. branching fraction measured be...
The first observation of the decays <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi>J</a:mi><a:mo>/</a:mo><a:mi>ψ</a:mi><a:mo stretchy="false">→</a:mo><a:mover accent="true"><a:mrow><a:mi>p</a:mi></a:mrow><a:mrow><a:mo stretchy="false">¯</a:mo></a:mrow></a:mover><a:msup><a:mrow><a:mi...
The process <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>e</a:mi><a:mo>+</a:mo></a:msup><a:msup><a:mi>e</a:mi><a:mo>−</a:mo></a:msup><a:mo stretchy="false">→</a:mo><a:msup><a:mi mathvariant="normal">Σ</a:mi><a:mo>+</a:mo></a:msup><a:msup><a:mover accent="true"><a:mi mathvariant="normal">Σ</a:mi><a:mo stretchy="false">¯</a:mo></a:mover><a:mo>−</a:mo></a:msup></a:math> is studied from threshold up to <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"...
Based on a data sample of 10 billion <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>J</a:mi><a:mo>/</a:mo><a:mi>ψ</a:mi></a:math> events collected with the BESIII detector, improved measurements Dalitz decays <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>η</c:mi><c:mo>/</c:mo><c:msup><c:mi>η</c:mi><c:mo>′</c:mo></c:msup><c:mo...
Based on <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mo stretchy="false">(</a:mo><a:mn>27.12</a:mn><a:mo>±</a:mo><a:mn>0.14</a:mn><a:mo stretchy="false">)</a:mo><a:mo>×</a:mo><a:msup><a:mn>10</a:mn><a:mn>8</a:mn></a:msup><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi>ψ</a:mi><a:mo stretchy="false">(</a:mo><a:mn>2</a:mn><a:mi>S</a:mi><a:mo stretchy="false">)</a:mo></a:math> events collected by the BESIII detector, we search for decay <g:math...
In this Letter we try to search for signals generated by ultraheavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look possible γ rays annihilation or decay from 16 dwarf spheroidal galaxies in field of view LHAASO. Dwarf are among most promising targets indirect detection that have low fluxes astrophysical γ-ray background while having large amount matter. By analyzing more than 700 days observational data LHAASO, no significant signal 1 TeV EeV is...
The decay $J/\psi \rightarrow \gamma \phi$ is studied using a sample of $1.31 \times10^{9}$ $J/\psi$ events collected with the BESIII detector. Two structures around 1475 MeV/c$^2$ and 1835 are observed in $\gamma invariant mass spectrum for first time. With fit on mass, which takes into account interference between two structures, simple analysis angular distribution, structure found to favor an assignment as $\eta(1475)$ width consistent $X(1835)$. statistical significances $13.5 \sigma$...
Based on a sample of $4.\text{5 }{\mathrm{fb}}^{\ensuremath{-}1}$ ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data collected in the energy region between 4.6 GeV and 4.7 with BESIII detector at BEPCII, two singly Cabibbo-suppressed decays ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Sigma}}}^{0}{K}^{+}$ ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Sigma}}}^{+}{K}_{S}^{0}$ are studied. The ratio branching...
Using data samples collected with the BESIII detector at center-of-mass energies $\sqrt{s}=4.23$, 4.26, 4.36, and 4.42 GeV, we measure branching fractions of ${\ensuremath{\eta}}_{c}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$, ${K}_{S}^{0}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}$, $2({\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0})$, $p\overline{p}$, via process...