K. Chilikin
A5061154081- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Medical Imaging Techniques and Applications
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Advanced NMR Techniques and Applications
- Cosmology and Gravitation Theories
- Physics of Superconductivity and Magnetism
- Astrophysics and Cosmic Phenomena
- International Science and Diplomacy
- Cold Atom Physics and Bose-Einstein Condensates
- Scientific Computing and Data Management
- Particle accelerators and beam dynamics
- Calibration and Measurement Techniques
- Distributed and Parallel Computing Systems
- Atomic and Molecular Physics
- Gamma-ray bursts and supernovae
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
2016-2023
Korea Institute of Science & Technology Information
2023
Duke University
2019-2020
University of Cincinnati
2019-2020
Chonnam National University
2018-2020
University of the Basque Country
2018-2020
University of Florida
2020
Beihang University
2018-2019
Karlsruhe Institute of Technology
2019
Institute of Engineering Physics
2016-2018
We report a measurement of the branching fraction ratios R(D(*)) Bbar -> D(*) tau- nubar_tau relative to D()* l- nubar_l (where l = e or mu) using full Belle data sample 772 x 10^6 BBbar pairs collected at Y(4S) resonance with detector KEKB asymmetric-energy e+e- collider. The measured values are R(D)= 0.375 +- 0.064(stat.) 0.026(syst.) and R(D*) 0.293 0.038(stat.) 0.015(syst.). analysis uses hadronic reconstruction tag-side B meson purely leptonic tau decays. results consistent earlier...
We report the observation of two narrow structures in mass spectra pi+-Y(nS) (n=1,2,3) and pi+-hb(mP)(m$ (m=1,2) pairs that are produced association with a single charged pion Y(5S) decays. The measured masses widths averaged over five final states M_1=(10607.2+-2.0) MeV/c2, Gamma_1=(18.4+-2.4) MeV M_2=(10652.2+-1.5) Gamma_2=(11.5+-2.2) MeV. results obtained 121.4 1/fb data sample collected Belle detector vicinity resonance at KEKB asymmetric-energy e+e- collider.
We report the first measurement of $\ensuremath{\tau}$ lepton polarization ${P}_{\ensuremath{\tau}}({D}^{*})$ in decay $\overline{B}\ensuremath{\rightarrow}{D}^{*}{\ensuremath{\tau}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\tau}}$ as well a new ratio branching fractions...
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...
We present a measurement of angular observables and test lepton flavor universality in the $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ decay, where $\ensuremath{\ell}$ is either $e$ or $\ensuremath{\mu}$. The analysis performed on data sample corresponding to an integrated luminosity $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ containing $772\ifmmode\times\else\texttimes\fi{}1{0}^{6}$ $B\overline{B}$ pairs, collected at...
The experimental results on the ratios of branching fractions R(D)=B(B[over ¯]→Dτ^{-}ν[over ¯]_{τ})/B(B[over ¯]→Dℓ^{-}ν[over ¯]_{ℓ}) and R(D^{*})=B(B[over ¯]→D^{*}τ^{-}ν[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ}), where ℓ denotes an electron or a muon, show long-standing discrepancy with standard model predictions, might hint at violation lepton flavor universality. We report new simultaneous measurement R(D) R(D^{*}), based data sample containing 772×10^{6} BB[over ¯] events recorded ϒ(4S) resonance...
With the full data sample of $772 \times 10^6$ $B{\bar B}$ pairs recorded by Belle detector at KEKB electron-positron collider, decay $\bar{B} \rightarrow D^* \tau^- \bar{\nu}_\tau$ is studied with hadronic $\tau$ decays $\tau^- \pi^- \nu_\tau$ and \rho^- \nu_\tau$. The polarization $P_\tau(D^*)$ in two-body measured, as well ratio branching fractions $R(D^{*}) = \mathcal{B}(\bar {B} \bar{\nu}_\tau) / \mathcal{B}(\bar{B} \ell^- \bar{\nu}_\ell)$, where $\ell^-$ denotes an electron or a muon....
We present a measurement of ${R}_{{K}^{*}}$, the branching fraction ratio $\mathcal{B}(B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})/\mathcal{B}(B\ensuremath{\rightarrow}{K}^{*}{e}^{+}{e}^{\ensuremath{-}})$, for both charged and neutral $B$ mesons. The case ${R}_{{K}^{*+}}$ is first ever performed. In addition, we report absolute fractions individual modes in bins squared dilepton invariant mass ${q}^{2}$. analysis based on data sample $711\text{...
We present measurements of the branching fractions for decays $B\to K \mu^{+}\mu^{-}$ and e^{+}e^{-}$, their ratio ($R_{K}$), using a data sample 711 $fb^{-1}$ that contains $772 \times 10^{6}$ $B\bar{B}$ events. The were collected at $\Upsilon(4S)$ resonance with Belle detector KEKB asymmetric-energy $e^{+}e^{-}$ collider. $R_{K}$ is measured in five bins dilepton invariant-mass-squared ($q^{2}$): $q^{2} \in (0.1, 4.0), (4.0, 8.12), (1.0, 6.0)$, $(10.2, 12.8)$ ($>14.18) GeV^{2}/c^{4}$,...
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 report a measurement of the process $\ensuremath{\gamma}{\ensuremath{\gamma}}^{*}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}$ with $759\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample recorded Belle detector at KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. The pion transition form factor, $F({Q}^{2})$, is measured for kinematical region $4\text{ }{\mathrm{GeV}}^{2}\ensuremath{\lesssim}{Q}^{2}\ensuremath{\lesssim}40\text{ }{\mathrm{GeV}}^{2}$, where...
We perform a full amplitude analysis of B0→ψ′K+π− decays, with ψ′→μ+μ− or e+e−, to constrain the spin and parity Z(4430)−. The JP=1+ hypothesis is favored over 0−, 1−, 2− 2+ hypotheses at levels 3.4σ, 3.7σ, 4.7σ 5.1σ, respectively. based on 711 fb−1 data sample that contains 772×106 BB¯ pairs collected Υ(4S) resonance by Belle detector asymmetric-energy e+e− collider KEKB.7 MoreReceived 20 June 2013DOI:https://doi.org/10.1103/PhysRevD.88.074026© 2013 American Physical Society
We present results from a study of $X(3872)\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\pi}J/\ensuremath{\psi}$ decays produced via exclusive $B\ensuremath{\rightarrow}KX(3872)$ decays. determine the mass to be ${M}_{X(3872)}=(3871.85\ifmmode\pm\else\textpm\fi{}0.27(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.19(\mathrm{syst}))\text{ }\text{ }\mathrm{MeV}$, 90% confidence level upper limit on natural width ${\ensuremath{\Gamma}}_{X(3872)}<1.2\text{ product branching fraction...
We present the results of an amplitude analysis anti-B0 -> J/psi K- pi+ decays. A new charged charmoniumlike state Zc(4200)+ decaying to is observed with a significance 6.2 sigma. The mass and width are 4196 +31-29 +17-13 MeV/c^2 370 +70-70 +70-132 MeV, respectively; preferred assignment quantum numbers J^P = 1^+. In addition, we find evidence for Zc(4430)+ pi+. based on 711 fb^-1 data sample collected by Belle detector at asymmetric-energy e+ e- collider KEKB.
We measure the branching fraction of B−→τ−¯ντ using full Υ(4S) data sample containing 772×106 B¯¯¯B pairs collected with Belle detector at KEKB asymmetric-energy e+e− collider. Events are tagged by reconstructing one B mesons decaying into hadronic final states, and candidates detected in recoil. find evidence for a significance 3.0 standard deviations including systematic errors B(B−→τ−¯ντ)=[0.72+0.27−0.25(stat)±0.11(syst)]×10−4.Received 16 November...
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 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 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 the results of a study exclusive semileptonic decays B->pi0lnu, B->pi+lnu, B->rho0lnu, B->rho+lnu and B->omegalnu, where l represents an electron or muon. The events are tagged by fully reconstructing second B meson in event hadronic decay mode. measured branching fractions Br(B->pi0lnu) = (0.80 +- 0.08 0.04)x10^-4, Br(B->pi+lnu) (1.49 0.09 0.07)x10^-4, Br(B->rho0lnu) (1.83 0.10 0.10)x10^-4, Br(B->rho+lnu) (3.22 0.27 0.24)x10^-4, Br(B->omegalnu) =(1.07 0.16 first error is...
We present a measurement of angular observables and test lepton flavor universality in the $B\to K^\ast \ell^+\ell^-$ decay, where $\ell$ is either $e$ or $μ$. The analysis performed on data sample corresponding to an integrated luminosity $711~\mathrm{fb}^{-1}$ containing $772\times 10^{6}$ $B\bar B$ pairs, collected at $Υ(4S)$ resonance with Belle detector asymmetric-energy $e^+e^-$ collider KEKB. result consistent Standard Model (SM) expectations, largest discrepancy from SM prediction...
We present a measurement of angular observables, $P_4'$, $P_5'$, $P_6'$, $P_8'$, in the decay $B^0 \to K^\ast(892)^0 \ell^+ \ell^-$, where $\ell^+\ell^-$ is either $e^+e^-$ or $\mu^+\mu^-$. The analysis performed on data sample corresponding to an integrated luminosity $711~\mathrm{fb}^{-1}$ containing $772\times 10^{6}$ $B\bar B$ pairs, collected at $\Upsilon(4S)$ resonance with Belle detector asymmetric-energy collider KEKB. Four $P_{4,5,6,8}'$ are extracted five bins invariant mass...
We present a precise measurement of the CP violation parameter sin2phi_1 and direct A_f using final data sample 772x10^6 B\bar B pairs collected at Upsilon(4S) resonance with Belle detector KEKB asymmetric-energy e+e- collider. One neutral meson is reconstructed in J/psi K0S, psi(2S) chi_c1 K0S or K0L CP-eigenstate its flavor identified from decay products accompanying meson. From distribution proper time intervals between two decays, we obtain following parameters:...
We present a new measurement of the Cabibbo-Kobayashi-Maskawa matrix element $|{V}_{cb}|$ from ${B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}$ decays, reconstructed with full Belle data set $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity. Two form factor parametrizations, originally conceived by Caprini-Lellouch-Neubert (CLN) and Boyd, Grinstein Lebed (BGL) groups, are used to extract product...
We report a measurement of the ratios branching fractions $\mathcal{R}(D) = {\cal B}(\bar{B} \to D \tau^- \bar{\nu}_{\tau})/{\cal \ell^- \bar{\nu}_{\ell})$ and $\mathcal{R}(D^{\ast}) D^* \bar{\nu}_{\ell})$, where $\ell$ denotes an electron or muon. The results are based on data sample containing $772\times10^6$ $B\bar{B}$ events recorded at $\Upsilon(4S)$ resonance with Belle detector KEKB $e^+ e^-$ collider. analysis utilizes method tag-side $B$ meson is reconstructed in semileptonic decay...