Y.-J. Kwon
A5011111291- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Atomic and Subatomic Physics Research
- Medical Imaging Techniques and Applications
- Radio Astronomy Observations and Technology
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Gamma-ray bursts and supernovae
- Lightning and Electromagnetic Phenomena
- Physics of Superconductivity and Magnetism
- Ionosphere and magnetosphere dynamics
- Cosmology and Gravitation Theories
- Nuclear physics research studies
- Advanced NMR Techniques and Applications
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Photocathodes and Microchannel Plates
Yonsei University
2015-2024
Inha University
2019-2023
Korea Institute of Science & Technology Information
2023
Chungnam National University Hospital
2023
Kyungpook National University Hospital
2023
University of the Basque Country
2013-2022
Duke University
2022
Campbell Collaboration
2012-2022
University of Bonn
2013-2022
Chonnam National University
2018-2022
The cross section for ee+ e- → π+ π- J/ψ between 3.8 and 5.5 GeV is measured with a 967 fb(-1) data sample collected by the Belle detector at or near Υ(nS) (n = 1,2,…,5) resonances. Y(4260) state observed, its resonance parameters are determined. In addition, an excess of production around 4 observed. This feature can be described Breit-Wigner parametrization properties that consistent Y(4008) was previously reported Belle. study decays, structure observed in M(π(±)J/ψ) mass spectrum 5.2σ...
We have measured the inclusive $b\ensuremath{\rightarrow}s\ensuremath{\gamma}$ branching ratio to be $(2.32\ifmmode\pm\else\textpm\fi{}0.57\ifmmode\pm\else\textpm\fi{}0.35)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$, where first error is statistical and second systematic. Upper lower limits on ratio, each at 95% C.L., are $B(b\ensuremath{\rightarrow}s\ensuremath{\gamma})<4.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$...
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 report a measurement of the ratio ${\cal R}(D^*) = {\cal B}(\bar{B}^0 \rightarrow D^{*+} \tau^- \bar{\nu}_{\tau})/{\cal \ell^- \bar{\nu}_{\ell})$, where $\ell$ denotes an electron or muon. The results are based on data sample containing $772\times10^6$ $B\bar{B}$ pairs recorded at $\Upsilon(4S)$ resonance with Belle detector KEKB $e^+ e^-$ collider. select $B^0 \bar{B}^0$ by reconstructing both $B$ mesons in semileptonic decays to $D^{*\mp} \ell^{\pm}$. measure R}(D^*)= 0.302 \pm...
The Telescope Array (TA) experiment, located in the western desert of Utah,USA, is designed for observation extensive air showers from extremely high energy cosmic rays. experiment has a surface detector array surrounded by three fluorescence detectors to enable simultaneous detection shower particles at ground level and photons along track. TA started full hybrid March, 2008. In this article we describe design technical features detector.
The Belle experiment, running at the KEKB e+e− asymmetric energy collider during first decade of century, achieved its original objective precisely measuring differences between particles and antiparticles in B system. After collecting 1000 fb−1 data various Υ resonances, also obtained many other physics results described this article.
We have searched for intermediate-scale anisotropy in the arrival directions of ultrahigh-energy cosmic rays with energies above 57~EeV northern sky using data collected over a 5 year period by surface detector Telescope Array experiment. report on cluster events that we call hotspot, found oversampling 20$^\circ$-radius circles. The hotspot has Li-Ma statistical significance 5.1$\sigma$, and is centered at R.A.=146.7$^{\circ}$, Dec.=43.2$^{\circ}$. position about 19$^{\circ}$ off...
The Telescope Array (TA) collaboration has measured the energy spectrum of ultra-high cosmic rays with primary energies above 1.6 x 10^(18) eV. This measurement is based upon four years observation by surface detector component TA. shows a dip at an 4.6 eV and steepening 5.4 10^(19) which consistent expectation from GZK cutoff. We present results technique, new to analysis ray data, that involves generating complete simulation striking TA detector. procedure starts shower simulations using...
We report a measurement of the exclusive e+ e- -->Lambda+_(c)Lambda-_(c) cross section as function center-of-mass energy near Lambda+_(c)Lambda-_(c) threshold. A clear peak with significance 8.2sigma is observed in invariant mass distribution just above With an assumption resonance origin for peak, and width M=[4634 (+8)_(-7)(stat)(+5)_(-8)(syst)] MeV/c(2) Gamma_(tot)=[92 (+40)_(-24)(stat)(+10)_(-21)(syst)] MeV are determined. The analysis based on study events initial-state-radiation...
We present an improved measurement of the standard model CP violation parameter $\mathrm{sin}2{\ensuremath{\varphi}}_{1}$ (also known as $\mathrm{sin}2\ensuremath{\beta})$ based on a sample $85\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected at $\ensuremath{\Upsilon}(4S)$ resonance with Belle detector KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. One neutral B meson is reconstructed in $J/\ensuremath{\psi}{K}_{S}^{0},$...
We present the results of a search for rare decays $B\to h\nu\overline{\nu}$, where $h$ stands $K^+,\:K^0_{\mathrm{S}},\:K^{\ast +},\:K^{\ast 0},\:\pi^+,\:\pi^0,\:\rho^+$ and $\rho^{0}$. The are obtained with $772\times10^{6}$ $B\overline{B}$ pairs collected Belle detector at KEKB $e^+ e^-$ collider. reconstruct one $B$ meson in semileptonic decay require single but nothing else on signal side. observe no significant set upper limits branching fractions. K^0_{\mathrm{S}}\nu\overline{\nu}$,...
We present a determination of the magnitude Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ using decay $B\to D\ell\nu_\ell$ ($\ell=e,\mu$) based on 711 fb$^{-1}$ $e^+e^-\to \Upsilon(4S)$ data recorded by Belle detector and containing $772 \times 10^6$ $B\bar{B}$ pairs. One $B$ meson in event is fully reconstructed hadronic mode while other, signal side, partially from charged lepton either $D^+$ or $D^0$ total 23 modes. The isospin-averaged branching fraction found to be...
We report measurement of the cross section $e^+e^-\to \pi^+\pi^-\psi(2S)$ between 4.0 and $5.5 {\rm GeV}$, based on an analysis initial state radiation events in a $980 \rm fb^{-1}$ data sample recorded with Belle detector. The properties $Y(4360)$ $Y(4660)$ states are determined. Fitting mass spectrum $\pi^+\pi^-\psi(2S)$ two coherent Breit-Wigner functions, we find solutions identical width but different couplings to electron-positron pairs: $M_{Y(4360)} = (4347\pm 6\pm 3) MeV}/c^2$,...
We report a study of $B\to (J/\psi \gamma) K$ and (\psi' \gamma)K$ decay modes using $772\times 10^{6}$ $B\bar{B}$ events collected at the \Upsilon(4S)$ resonance with Belle detector KEKB energy-asymmetric $e^+ e^-$ collider. observe $X(3872) \to J/\psi \gamma$ first evidence for $\chi_{c2} in (X_{c\bar{c}}\gamma) decays, while search \psi' no significant signal is found. measure branching fractions, $\mathcal{B}(B^{\pm} X(3872) K^{\pm}) \mathcal{B}(X(3872) J/\psi\gamma)$ $=$...
We report on a search for heavy neutrinos in B-meson decays. The results are obtained using data sample that contains 772x10^6 BB-bar pairs collected at the Upsilon(4S) resonance with Belle detector KEKB asymmetric-energy e+e- collider. No signal is observed and upper limits set mixing of left-handed Standard Model mass range 0.5 - 5.0 GeV/c^2.
We present a measurement of the charmless semileptonic decay $B^0\to\pi^-\ell^+\nu$ using data sample containing 657$\times 10^6$ $B\bar{B}$ events collected with Belle detector at KEKB asymmetric-energy $e^+e^-$ collider operating near $\Upsilon(4S)$ resonance. determine total branching fraction decay, $\mathcal{B}(B^0\to\pi^-\ell^+\nu)=(1.49\pm 0.04{(\mathrm{stat})}\pm 0.07{(\mathrm{syst})})\times 10^{-4}$. also report new precise differential rate, and extract Cabibbo-Kobayashi-Maskawa...
We report on a measurement of the cosmic ray energy spectrum by Telescope Array Low-Energy Extension (TALE) air fluorescence detector. The TALE detector is also sensitive to Cherenkov light produced shower particles. Low rays, in PeV range, are detectable as "Cherenkov Events". Using these events, we measure from low $\sim 2$ an greater than 100 PeV. Above can detect rays using fluorescence. This allows for extension energies few EeV. In this paper, will describe detector, explain technique,...
Using the entire Belle data sample of 980 ${\rm fb}^{-1}$ $e^+e^-$ collisions, we present results a study excited $\Omega_c$ charmed baryons in decay mode $\Xi_c^+K^-$. We show confirmation four five narrow states reported by LHCb Collaboration: $\Omega_c(3000)$ , $\Omega_c(3050)$, $\Omega_c(3066)$, and $\Omega_c(3090)$.
We report on a study of the invariant mass spectrum hadronic system in decay ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}{\ensuremath{\nu}}_{\ensuremath{\tau}}.$ This was performed with data obtained CLEO II detector operating at CESR ${e}^{+}{e}^{\ensuremath{-}}$ collider. present fits to phenomenological models which resonance parameters associated $\ensuremath{\rho}(770)$ and $\ensuremath{\rho}(1450)$ mesons are...
We report results on a Dalitz analysis of three-body charmless ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}$ decay including searches for direct $CP$ violation. the first observation ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{f}_{2}(1270){K}^{\ifmmode\pm\else\textpm\fi{}}$ with statistical significance above $6\ensuremath{\sigma}$. also...