P. Krokovny
A5076304854- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Medical Imaging Techniques and Applications
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Nuclear physics research studies
- Distributed and Parallel Computing Systems
- Stochastic processes and statistical mechanics
- Advanced NMR Techniques and Applications
- Cosmology and Gravitation Theories
- Particle accelerators and beam dynamics
- Astrophysics and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- International Science and Diplomacy
- Radioactive Decay and Measurement Techniques
- Cold Atom Physics and Bose-Einstein Condensates
- Nuclear Physics and Applications
- Pulsars and Gravitational Waves Research
Budker Institute of Nuclear Physics
2016-2025
European Organization for Nuclear Research
2015-2025
Siberian Branch of the Russian Academy of Sciences
2015-2024
Novosibirsk State University
2015-2024
Universitat Ramon Llull
2023-2024
Universitat de Barcelona
2018-2024
Universidade de Santiago de Compostela
2013-2024
Novosibirsk State Technical University
2014-2024
Institute of Nuclear Physics, Polish Academy of Sciences
2024
AGH University of Krakow
2024
We report the observation of a narrow charmoniumlike state produced in exclusive decay process B+/--->K+/-pi(+)pi(-)J/psi. This state, which decays into pi(+)pi(-)J/psi, has mass 3872.0+/-0.6(stat)+/-0.5(syst) MeV, value that is very near M(D0)+M(D(*0)) threshold. The results are based on an analysis 152M B-Bmacr; events collected at Upsilon(4S) resonance Belle detector KEKB collider. signal statistical significance excess 10sigma.
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 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...
A distinct peak is observed in the ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\psi}}^{\ensuremath{'}}$ invariant mass distribution near 4.43 GeV $B\ensuremath{\rightarrow}K{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\psi}}^{\ensuremath{'}}$ decays. fit using a Breit-Wigner resonance shape yields and width of $M=4433\ifmmode\pm\else\textpm\fi{}4(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}2(\mathrm{syst})\text{ }\text{ }\mathrm{MeV}$...
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 study B→K(*)ℓ+ℓ− decays (ℓ=e, μ) based on a data sample of 657×106 BB¯ pairs collected with the Belle detector at KEKB e+e− collider. report differential branching fraction, isospin asymmetry, K* polarization, and forward-backward asymmetry (AFB) as functions q2=Mℓℓ2c2. The fitted AFB spectrum exceeds standard model expectation by 2.7 deviations. measured fractions are B(B→K*ℓ+ℓ−)=(10.7−1.0+1.1±0.9)×10−7 B(B→Kℓ+ℓ−)=(4.8−0.4+0.5±0.3)×10−7, where first errors statistical second systematic,...
The cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\psi}(2S)$ between threshold and $\sqrt{s}=5.5\text{ }\text{ }\mathrm{GeV}$ is measured using $673\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data on off the $\ensuremath{\Upsilon}(4S)$ resonance collected with Belle detector at KEKB. Two resonant structures are observed in...
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 cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$ between 3.8 and $5.5\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ is measured using a $548\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample collected on or near the $\ensuremath{\Upsilon}(4S)$ resonance with Belle detector at KEKB. A peak $4.25\text{ }\mathrm{GeV}/{c}^{2}$, corresponding to so called $Y(4260)$, observed. In addition, there another...
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 ($q^{2}$): $q^{2} \in (0.1, 4.0), (4.0, 8.12), (1.0, 6.0)$, $(10.2, 12.8)$ ($>14.18) GeV^{2}/c^{4}$,...
The cross section of 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>π</a:mi><a:mo>+</a:mo></a:msup><a:msup><a:mi>π</a:mi><a:mo>−</a:mo></a:msup></a:math> has been measured in center mass energy range from 0.32 to 1.2 GeV with CMD-3 detector at electron-positron collider VEPP-2000. measurement is based on a full dataset...
The cross section of 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>π</a:mi><a:mo>+</a:mo></a:msup><a:msup><a:mi>π</a:mi><a:mo>−</a:mo></a:msup></a:math> has been measured in center-of-mass energy range from 0.32 to 1.2 GeV with CMD-3 detector at electron-positron collider VEPP-2000. measurement is based on an integrated...
We report the observation of a near-threshold enhancement in omegaJ/psi invariant mass distribution for exclusive B-->KomegaJ/psi decays. The results are obtained from 253 fb(-1) data sample that contains 275 x 10(6) BB pairs were collected near Upsilon(4S) resonance with Belle detector at KEKB asymmetric energy e(+)e(-) collider. statistical significance is estimated to be greater than 8sigma.
We report the observation of prompt J/psi via double cc; production from e+e- continuum. In this process one pair fragments into a meson while remaining either produces charmonium state or open charm. Both cases have been experimentally observed. find cross sections sigma[e+e- -->J/psieta(c)(gamma)]xB(eta(c)-->>or=4 charged)=(0.033(+0.007)(-0.006)+/-0.009) pb and sigma(e+e- -->J/psiD(*+)X)=(0.53(+0.19)(-0.15)+/-0.14) infer -->J/psicc;)/sigma(e+e- -->J/psiX)=0.59(+0.15)(-0.13)+/-0.12. These...
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 report the results of a study charged B decays to D+- pi-+ and D*+- final states using complete D(*) reconstruction. The contributions two-body => D** pi with narrow (j=3/2) broad (j=1/2) have been determined masses widths four measured. This is first observation D*0_0 D'0_1 mesons. analysis based on data sample 65 million barB pairs collected in Belle experiment.
We report the first observation of B-->Dmacr;D(sJ)(2317) and B-->Dmacr;D(sJ)(2457) decays based on 123.8x10(6) BBmacr; events collected with Belle detector at KEKB. observe D(sJ)(2317) decay to D(s)pi(0) D(sJ)(2457) D(*)(s)pi(0) D(s)gamma final states. also set 90% C.L. upper limits for D(sJ)(2317)-->D(*)(s)gamma, D(sJ)(2457)-->D(*)(s)gamma, D(sJ)(2457)-->D(s)pi(0), D(sJ)(2457)-->D(s)pi(+)pi(-).