B. G. Cheon
A5017920247- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Physics of Superconductivity and Magnetism
- Gamma-ray bursts and supernovae
- Advanced NMR Techniques and Applications
- Peptidase Inhibition and Analysis
- Radiation Therapy and Dosimetry
- Muon and positron interactions and applications
- NMR spectroscopy and applications
- Magnetic properties of thin films
- Molecular Spectroscopy and Structure
- Plant nutrient uptake and metabolism
- Cold Atom Physics and Bose-Einstein Condensates
Hanyang University
2014-2025
Institute of Natural Science
2020-2022
Korea University
2019
Justus-Liebig-Universität Gießen
2013
Gifu University
2013
University of Bonn
2013
University of the Basque Country
2013
University of Cincinnati
2013
Chonnam National University
2004-2008
National United University
2005-2008
We search for the rare decay <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>B</a:mi><a:mo>+</a:mo></a:msup><a:mo stretchy="false">→</a:mo><a:msup><a:mi>K</a:mi><a:mo>+</a:mo></a:msup><a:mi>ν</a:mi><a:mover accent="true"><a:mi>ν</a:mi><a:mo stretchy="false">¯</a:mo></a:mover></a:math> in a <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:mn>362</f:mn><f:mtext> </f:mtext><f:mtext>...
We observe evidence for D0−¯¯¯D0 mixing by measuring the difference in apparent lifetime when a D0 meson decays to CP eigenstates K+K− and π+π− it final state K−π+. find relative of lifetimes yCP be [1.31±0.32(stat)±0.25(syst)]%, 3.2 standard deviations from zero. also search asymmetry between ¯¯¯D0 decays; no violation is found. These results are based on 540 fb−1 data recorded Belle detector at KEKB e+e− collider.Received 31 March 2007DOI:https://doi.org/10.1103/PhysRevLett.98.211803©2007...
We report the first observations of spin-singlet bottomonium states hb(1P) and hb(2P). The are produced in reaction e+e−→hb(nP)π+π− using a 121.4 fb−1 data sample collected at energies near Υ(5S) resonance with Belle detector KEKB asymmetric-energy e+e− collider. determine M[hb(1P)]=(9898.2+1.1+1.0−1.0−1.1) MeV/c2 M[hb(2P)]=(10 259.8±0.6+1.4−1.0) MeV/c2, which correspond to P-wave hyperfine splittings ΔMHF=(+1.7±1.5) (+0.5+1.6−1.2) respectively. significances hb(2P) 5.5σ 11.2σ, find that...
We present a search for the direct production of light pseudoscalar decaying into two photons with Belle II detector at SuperKEKB collider. process e^{+}e^{-}→γa, a→γγ in mass range 0.2<m_{a}<9.7 GeV/c^{2} using data corresponding to an integrated luminosity (445±3) pb^{-1}. Light pseudoscalars interacting predominantly standard model gauge bosons (so-called axionlike particles or ALPs) are frequently postulated extensions model. find no evidence ALPs and set 95% confidence level upper...
We present a measurement of the differential shapes exclusive $B\ensuremath{\rightarrow}{D}^{*}\ensuremath{\ell}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}$ ($B={B}^{\ensuremath{-}},{\overline{B}}^{0}$ and $\ensuremath{\ell}=e$, $\ensuremath{\mu}$) decays with hadronic tag-side reconstruction for full $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ Belle dataset. extract Caprini-Lellouch-Neubert (CLN) Boyd-Grinstein-Lebed (BGL) form factor parameters use an external input absolute...
We report the observation of a narrow peak in K(S)K-pi(+) invariant mass distribution sample exclusive B-->KK(S)K-pi(+) decays collected with Belle detector at KEKB asymmetric e(+)e(-) collider. The measured is M=3654+/-6(stat)+/-8(syst) MeV/c(2), and we place 90% confidence level upper limit on width Gamma<55 MeV/c(2). properties agree heavy-quark potential model expectations for eta(c)(2S) meson, n=2 singlet S charmonium state.
We report evidence for direct CP violation in the decay B0-->K+pi(-) with 253 fb(-1) of data collected Belle detector at KEKB e(+)e(-) collider. Using 275x10(6) BB pairs we observe a B-->K+/-pi(-/+) signal 2140+/-53 events. The measured violating asymmetry is A(CP)(K+pi(-))=-0.101+/-0.025(stat)+/-0.005(syst), corresponding to significance 3.9sigma including systematics. also search decays B+-->K+pi(0) and B+-->pi(+)pi(0). asymmetries are A(CP)(K+pi(0))=0.04+/-0.05(stat)+/-0.02(syst)...
We report measurements of the exclusive cross section for e+e−→D¯¯¯D, where D=D0 or D+, in center-of-mass energy range from D¯¯¯D threshold to 5 GeV with initial-state radiation. The analysis is based on a data sample collected Belle detector an integrated luminosity 673 fb−1.Received 18 October 2007DOI:https://doi.org/10.1103/PhysRevD.77.011103©2008 American Physical Society
The cross sections for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\phi}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\phi}{f}_{0}(980)$ are measured from threshold to $\sqrt{s}=3.0\text{ }\text{ }\mathrm{GeV}$ using initial-state radiation. analysis is based on a data sample of $673\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected below the $\ensuremath{\Upsilon}(4S)$ resonance with Belle...
We present improved measurements of $CP$-violation parameters in ${B}^{0}\ensuremath{\rightarrow}\ensuremath{\phi}{K}^{0}$, ${\ensuremath{\eta}}^{\ensuremath{'}}{K}^{0}$, ${K}_{S}^{0}{K}_{S}^{0}{K}_{S}^{0}$ decays based on a sample $535\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected at the $\ensuremath{\Upsilon}(4S)$ resonance with Belle detector KEKB energy-asymmetric ${e}^{+}{e}^{\ensuremath{-}}$ collider. obtain...
The interference fragmentation function translates the of a quark with transverse projection spin into an azimuthal asymmetry two final-state hadrons. In e+e- annihilation product functions is measured. We report nonzero asymmetries for pairs charge-ordered pi+pi- pairs, which indicate significant in this channel. results are obtained from 672 fb-1 data sample that contains 711 \times 106 and was collected at near ?(4S) resonance, Belle detector KEKB asymmetric-energy collider.
We report measurements of B→χ(c1)γK and χ(c2)γK decays using 772×10(6) BB[over ¯] events collected at the Υ(4S) resonance with Belle detector KEKB asymmetric-energy e(+)e(-) collider. Evidence a new in χ(c1)γ final state is found statistical significance 3.8σ. This has mass 3823.1±1.8(stat)±0.7(syst) MeV/c(2), value that consistent theoretical expectations for previously unseen 1(3)D(2) cc[over meson. find no other narrow set upper limits on branching fractions X(3872)→χ(c1)γ χ(c2)γ decays.
We report the first evidence for ${\ensuremath{\eta}}_{b}(2S)$ using ${h}_{b}(2P)\ensuremath{\rightarrow}{\ensuremath{\eta}}_{b}(2S)\ensuremath{\gamma}$ transition and observation of ${h}_{b}(1P)\ensuremath{\rightarrow}{\ensuremath{\eta}}_{b}(1S)\ensuremath{\gamma}$ ${h}_{b}(2P)\ensuremath{\rightarrow}{\ensuremath{\eta}}_{b}(1S)\ensuremath{\gamma}$ transitions. The mass width ${\ensuremath{\eta}}_{b}(1S)$ are measured to be...
We perform a full amplitude analysis of the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}D\overline{D}$, where $D$ refers to either ${D}^{0}$ or ${D}^{+}$. A new charmoniumlike state ${X}^{*}(3860)$ that decays $D\overline{D}$ is observed with significance $6.5\ensuremath{\sigma}$. Its mass $({3862}_{\ensuremath{-}32}^{+26}{\text{ }}_{\ensuremath{-}13}^{+40})\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, and its width $({201}_{\ensuremath{-}67}^{+154}{\text{...
Received 25 April 2018DOI:https://doi.org/10.1103/PhysRevD.97.099902© 2018 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFlavor changing neutral currentsParticle decaysParticle interactionsParticles & Fields
We measure the ratio of branching fractions for $Υ(4S)$ decays to $B^+B^-$ and $B^0\bar{B}{}^0$ using $B^+ \rightarrow J/ψ(\ell\ell) K^+$ $B^0 K^0$ samples, where $J/ψ(\ell\ell)$ stands $J/ψ\to \ell^+\ell^-$ ($\ell = e$ or $μ$), with $711$ fb$^{-1}$ data collected at resonance Belle detector. find decay rate $Υ(4S) B^+B^-$ over B^0\bar{B}{}^0$ be $1.065\pm0.012\pm 0.019 \pm 0.047$, which is most precise measurement date. The first second uncertainties are statistical systematic,...
We measure the time-integrated <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>C</a:mi><a:mi>P</a:mi></a:math> asymmetry in <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msup><c:mi>D</c:mi><c:mn>0</c:mn></c:msup><c:mo stretchy="false">→</c:mo><c:msubsup><c:mi>K</c:mi><c:mi>S</c:mi><c:mn>0</c:mn></c:msubsup><c:msubsup><c:mi>K</c:mi><c:mi>S</c:mi><c:mn>0</c:mn></c:msubsup></c:math> decays reconstructed <f:math...
We measure the branching fraction of decay <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mrow><a:mi>B</a:mi></a:mrow><a:mrow><a:mn>0</a:mn></a:mrow></a:msup><a:mo stretchy="false">→</a:mo><a:mi>J</a:mi><a:mo>/</a:mo><a:mi>ψ</a:mi><a:mi>ω</a:mi></a:mrow></a:math> using data collected with Belle II detector at SuperKEKB collider. The contain <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:mrow><d:mo...
We present the first measurement of decay amplitudes in B→φK* and measurements branching fractions B→φK(*) decays based on 78.1 fb−1 data recorded at Υ(4S) resonance with Belle detector KEKB e+e− storage ring. The for different φK*0 helicity states are measured from angular distributions final state particles transversity basis. longitudinal transverse complex |A0|2=0.43±0.09±0.04, |A⊥|2=0.41±0.10±0.04, arg(A∥)=−2.57±0.39±0.09, arg(A⊥)=0.48±0.32±0.06. direct CP-violating asymmetries found to...
We report the results of several studies Lambda(c)(+)pi(+)pi(-)X final state in continuum e(+)e(-) annihilation data collected by Belle detector. An analysis angular distributions Lambda(c)(2880)(+)-->Sigma(c)(2455)(0,++)pi(+,-) decays strongly favors a Lambda(c)(2880)(+) spin assignment 5/2 over 3/2 or 1/2. find evidence for Lambda(c)(2880)(+)-->Sigma(c)(2520)(0,++)pi(+,-) decay and measure ratio partial widths Gamma(Sigma(c)(2520)pi)/Gamma(Sigma(c)(2455)pi)=0.225+/-0.062+/-0.025. This...
We report measurements of the exclusive cross section for e+e−→D0D*−π+ as a function center-of-mass energy from D0D*−π+ threshold to 5.2 GeV with initial-state radiation. No evidence is found Y(4260)→D0D*−π+ decays. The analysis based on data sample collected Belle detector at or near 10.58 an integrated luminosity 695 fb−1 KEKB asymmetric-energy e+e− collider.Received 4 August 2009DOI:https://doi.org/10.1103/PhysRevD.80.091101©2009 American Physical Society
We measure the production cross sections for e+e- -> Upsilon(1S)pi+pi-, Upsilon(2S)pi+pi-, and Upsilon(3S)pi+pi- as a function of sqrt{s} between 10.83 GeV 11.02 GeV. The data consists 8.1 fb^-1 collected with Belle detector at KEKB collider. observe enhanced in all three final states that does not agree well conventional Upsilon(10860) lineshape. A fit using Breit-Wigner resonance shape yields peak mass [10888.4 +2.7/-2.6 (stat) +- 1.2 (syst)] MeV/c^2 width [30.7 +8.3/-7.0 3.1 MeV/c^2.
We present a new measurement of the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}c\overline{c}$ cross section where $c\overline{c}$ pair can fragment either into charmed hadrons or charmonium state. In former case $J/\ensuremath{\psi}$ and hadron are reconstructed, while latter process is measured using recoil mass technique, which allows identification two-body final states without reconstruction one charmonia. The...