M. Shapkin
A5100679447- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Medical Imaging Techniques and Applications
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Stochastic processes and statistical mechanics
- Advanced NMR Techniques and Applications
- International Science and Diplomacy
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Markov Chains and Monte Carlo Methods
- Distributed and Parallel Computing Systems
- Advanced Data Storage Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Cosmology and Gravitation Theories
- Radioactive Decay and Measurement Techniques
- Particle accelerators and beam dynamics
European Organization for Nuclear Research
2015-2025
University of Oxford
2023-2024
Kurchatov Institute
2019-2024
University of Manchester
2023-2024
Imperial College London
2024
Institute for High Energy Physics
2013-2023
Tsinghua University
2023
Universitat de Barcelona
2023
University of Cincinnati
2023
Centro Brasileiro de Pesquisas Físicas
2017
The Belle detector at the KEKB electron-positron collider has collected almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an upgrade is under construction, to increase luminosity by two orders magnitude during a three-year shutdown, with ultimate goal 8E35 /cm^2 /s luminosity. To exploit increased luminosity, been proposed. A new international collaboration Belle-II, being formed. Technical Design Report presents physics motivation, basic methods accelerator upgrade, as...
We report the results of a search for charmonium-like state produced in process gamma --> omega J/psi 3.9-4.2 GeV/c^2 mass region. observe significant enhancement, which is well-described by resonant shape with M = (3915 +/- 3 2) MeV/c^2 and total width Gamma (17 10 3) MeV. This enhancement may be related to one or more three states so far reported 3.90-3.95
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
We present a study of $B\ensuremath{\rightarrow}X(3872)K$ with $X(3872)$ decaying to ${D}^{*0}{\overline{D}}^{0}$ using sample $657\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs recorded at the $\ensuremath{\Upsilon}(4S)$ resonance Belle detector KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. Both ${D}^{*0}\ensuremath{\rightarrow}{D}^{0}\ensuremath{\gamma}$ and ${D}^{*0}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}^{0}$ decay modes are used. find peak...
Using 605 fb−1 of data collected at the Υ(4S) resonance we present a measurement inclusive radiative B-meson decay channel, B→Xsγ. For lower photon energy thresholds 1.7, 1.8, 1.9, and 2.0 GeV, as defined in rest frame B meson, measure partial branching fraction mean variance spectrum. At 1.7 GeV threshold obtain BF(B→Xsγ)=(3.45±0.15±0.40)×10−4, where errors are statistical systematic.Received 8 July 2009DOI:https://doi.org/10.1103/PhysRevLett.103.241801©2009 American Physical Society
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 present a high-statistics measurement of differential cross sections and the total section for process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$ in kinematic range $0.6\text{ }\text{ }\mathrm{GeV}\ensuremath{\le}W\ensuremath{\le}4.0\text{ }\mathrm{GeV}$ $|\mathrm{cos}{\ensuremath{\theta}}^{*}|\ensuremath{\le}0.8$, where $W$ ${\ensuremath{\theta}}^{*}$ are energy pion scattering angle, respectively,...
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.
The differential cross section for the process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}\ensuremath{\eta}{\ensuremath{\pi}}^{0}$ has been measured in kinematic range $0.84\text{ }\text{ }\mathrm{GeV}<W<4.0\text{ }\mathrm{GeV}$, $|\mathrm{cos}{\ensuremath{\theta}}^{*}|<0.8$, where $W$ and ${\ensuremath{\theta}}^{*}$ are energy ${\ensuremath{\pi}}^{0}$ (or $\ensuremath{\eta}$) scattering angle, respectively, $\ensuremath{\gamma}\ensuremath{\gamma}$ center-of-mass system....
The cross section for e^+e^- \to \eta J/\psi between \sqrt{s}=3.8 GeV/c^2 and 5.3 is measured via initial state radiation using 980 fb^{-1} of data on around the \Upsilon(nS)(n=1,2,3,4,5) resonances collected with Belle detector at KEKB. Two resonant structures \psi(4040) \psi(4160) are observed in invariant mass distribution. Fitting spectrum coherent sum two Breit-Wigner functions, one obtains BR(\psi(4040)\to\eta J/\psi)\cdot\Gamma_{ee}^{\psi(4040)} = (4.8\pm0.9\pm1.4) eV...
We present a time-dependent Dalitz plot measurement of CP violation parameters in B0 --> Ks Pi+ Pi- decays. These results are obtained from large data sample that contains 657 million BBbar pairs collected at the Y(4S) resonance with Belle detector KEKB asymmetric-energy e+e- collider. For parameters, we obtain two consistent solutions describe well. The first these may be preferred by external information other measurements. There is no evidence for direct rho0(770) Ks, f0(980) and K*+(892)...
We search for the flavor-changing neutral current decays D0\to mu+mu- and e+e-, lepton-flavor violating e\pm mu\mp using 660 fb^-1 of data collected with Belle detector at KEKB asymmetric-energy e+e- collider. find no evidence any these decays. obtain significantly improved upper limits on branching fractions: B(D0\to mu+mu-)<1.4x10-7, e+e-)<7.9x10-8, e+mu-)+B(D0\to mu+e-)<2.6x10-7 90% confidence level.
The lifetime of the τ lepton is measured using process e+e−→τ+τ−, where both leptons decay to 3πντ. result for mean lifetime, based on 711 fb−1 data collected with Belle detector at Υ(4S) resonance and 60 MeV below, τ=(290.17±0.53(stat)±0.33(syst))×10−15 s. first measurement difference between τ+ τ− performed. upper limit relative positive negative |Δτ|/τ<7.0×10−3 90% C.L.Received 1 November 2013DOI:https://doi.org/10.1103/PhysRevLett.112.031801© 2014 American Physical Society
We have searched for $CP$ violation in the charmed meson decays ${D}_{(s)}^{+}\ensuremath{\rightarrow}{K}_{S}^{0}{\ensuremath{\pi}}^{+}$ and ${D}_{(s)}^{+}\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{+}$ using $673\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data collected with Belle detector at KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. No evidence is observed. report most sensitive asymmetry measurements to date these decays:...
We report on a search for $CP$ violation in ${\ensuremath{\tau}}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{K}_{S}^{0}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ decays using data sample of $699\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected by the Belle experiment at KEKB electron-positron asymmetric-energy collider. The asymmetry is measured four bins invariant mass...
We search for dimuon decays of a low mass particle in the ${B}^{0}\ensuremath{\rightarrow}{K}^{*0}X$ and ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{0}X$ using data sample $657\ifmmode\times\else\texttimes\fi{}{10}^{6}B\overline{B}$ events collected with Belle detector at KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. find no evidence such range from $212\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ to $300\text{ lifetimes below ${10}^{\ensuremath{-}12}\text{ }\mathrm{s}$,...
Decays of the $\ensuremath{\Upsilon}(5\mathrm{S})$ resonance to channels with ${B}^{+}$ and ${B}^{0}$ mesons are studied using a $23.6\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample collected Belle detector at KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. Fully reconstructed ${B}^{+}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{+}$, ${B}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{*0}$,...
Results of a study the $K^+ \rightarrow \pi^{0} e^{+} \nu \gamma $ decay at OKA setup are presented. More than 32000 events this observed. The differential spectra over photon energy and photon-electron opening angle in kaon rest frame branching ratios, normalized to that $K_{e3}$ calculated for different cuts $E^*_\gamma$ $cos\Theta^{*}_{e\gamma}$. In particular, ratio $E^{*}_{\gamma}>30$ MeV $\Theta^{*}_{e \gamma}>20^{\circ}$ is measured R = $\frac{Br(K^+ \nu_{e} \gamma) } {Br(K^+...
We report measurements of CP violation parameters in $B^0 \to K^0 \pi^0$ decays based on a data sample $657 \times 10^6 B\bar{B}$ pairs collected with the Belle detector at KEKB $e^+ e^-$ asymmetric-energy collider. use K^0_S for both mixing-induced and direct $CP$ violating asymmetry K^0_L measurement. The obtained are $\sin 2 \phi_1^{\rm eff} = +0.67 \pm 0.31{(stat)} 0.08 {(syst)}$ $\mathcal{A}_{K^0 \pi^0} +0.14 0.13{(stat)} 0.06 {(syst)}$. branching fraction decay is measured to be...
Using $535\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B$-meson pairs collected by the Belle detector at KEKB ${e}^{+}{e}^{\ensuremath{-}}$ collider, we measure branching fractions of $(7.16\ifmmode\pm\else\textpm\fi{}0.10(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.60(\mathrm{syst})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ for ${B}^{+}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and...
We report results on time-dependent $CP$ asymmetries in $B\ensuremath{\rightarrow}{D}^{*\ensuremath{\mp}}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ decays based a data sample containing $657\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected with the Belle detector at KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider $\ensuremath{\Upsilon}(4S)$ resonance. use partial reconstruction technique, wherein signal events are identified using information...
We report the first measurement of time-dependent CP asymmetry in B(0)-->K(S)(0)rho(0)gamma decays based on 657 x 10(6) BB pairs collected with Belle detector at KEKB asymmetric-energy collider. measure CP-violating parameter S_{K_{S};{0}rho;{0}gamma}=0.11+/-0.33(stat)-0.09+0.05(syst) from a signal 212+/-17 events. also obtain effective direct A{eff}=0.05+/-0.18(stat)+/-0.06(syst) for mK(S)0pi+pi- <1.8 GeV/c(2) and 0.6 GeV/c(2)<m pi+pi- <0.9 GeV/c2.
We report the first measurement of differential cross section for process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\eta}$ in kinematic range above $\ensuremath{\eta}\ensuremath{\eta}$ threshold, $1.096\text{ }\text{ }\mathrm{GeV}<W<3.8\text{ }\mathrm{GeV}$ over nearly entire solid angle range, $|\mathrm{cos}{\ensuremath{\theta}}^{*}|\ensuremath{\le}0.9$ or $\ensuremath{\le}1.0$ depending on $W$, where $W$ and...