A5027927955- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Black Holes and Theoretical Physics
- Medical Imaging Techniques and Applications
- CCD and CMOS Imaging Sensors
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Astrophysics and Cosmic Phenomena
- Radiation Effects in Electronics
- Advanced NMR Techniques and Applications
- Cosmology and Gravitation Theories
- Nuclear Physics and Applications
- Electron and X-Ray Spectroscopy Techniques
- Nuclear physics research studies
- Advanced Data Storage Technologies
- International Science and Diplomacy
- Hemoglobin structure and function
- Algebraic Geometry and Number Theory
Charles University
2015-2024
Deutsches Elektronen-Synchrotron DESY
2024
Austrian Academy of Sciences
2023
Korea Institute of Science & Technology Information
2023
Universitat de Barcelona
2023
Johannes Gutenberg University Mainz
2023
Ludwig-Maximilians-Universität München
2023
Technical University of Munich
2023
Max Planck Institute for Physics
2023
Halbleiterlabor of the Max-Planck-Society
2023
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...
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 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 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...
A search for the flavor-changing neutral-current decay B^{+}→K^{+}νν[over ¯] is performed at Belle II experiment SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63 fb^{-1} collected ϒ(4S) resonance and a 9 60 MeV below resonance. Because measurable signature involves only single charged kaon, novel measurement approach used that exploits not properties decay, but also inclusive other B meson in ϒ(4S)→BB[over event, suppress...
Abstract The Silicon Vertex Detector of Belle II is a state-of-the-art tracking and vertexing system based on double-sided silicon strip sensors, designed fabricated by large international collaboration in the period 2012–2018. Since 2019 it has been operation providing high quality data with small number defective channels (<1%), hit-finding efficiency (>99%), good signal-to-noise ratio (well excess 10 for all sensor configurations tracks). Together control over alignment, these are...
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,...
Abstract A series of data samples was collected with the Belle II detector at SuperKEKB collider from March 2019 to June 2022. We determine integrated luminosities these using three distinct methodologies involving Bhabha ( ), digamma and dimuon ) events. The total luminosity obtained Bhabha, digamma, events is (426.88 ± 0.03 2.61) fb −1 , (429.28 2.62) (423.99 0.04 3.83) where first uncertainties are statistical second systematic. resulting combination methods (427.87 2.01) .
We report the first observation of spontaneous polarization $\mathrm{\ensuremath{\Lambda}}$ and $\overline{\mathrm{\ensuremath{\Lambda}}}$ hyperons transverse to production plane in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation, which is attributed effect arising from a polarizing fragmentation function. For inclusive $\mathrm{\ensuremath{\Lambda}}/\overline{\mathrm{\ensuremath{\Lambda}}}$ production, we also results with subtracted feed-down contributions ${\mathrm{\ensuremath{\Sigma}}}^{0}$...
We report the first measurement of $D^{\ast -}$ meson polarization in decay $B^0 \to D^{*-} \tau^+\nu_{\tau}$ using full data sample 772$\times 10^6$ $B\bar{B}$ pairs recorded with Belle detector at KEKB electron-positron collider. Our result, $F_L^{D^\ast} = 0.60 \pm 0.08 ({\rm stat}) 0.04 sys})$, where $F_L^{D^\ast}$ denotes $D^{\ast-}$ longitudinal fraction, agrees within about $1.7$ standard deviations model prediction.
Using data recorded with the Belle detector, we observe a new excited hyperon, an Ω^{*-} candidate decaying into Ξ^{0}K^{-} and Ξ^{-}K_{S}^{0} mass of 2012.4±0.7(stat)±0.6(syst) MeV/c^{2} width Γ=6.4_{-2.0}^{+2.5}(stat)±1.6(syst) MeV. The is seen primarily in ϒ(1S),ϒ(2S), ϒ(3S) decays.
We present the first measurements of absolute branching fractions ${\mathrm{\ensuremath{\Xi}}}_{c}^{0}$ decays into ${\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, $\mathrm{\ensuremath{\Lambda}}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, and $p{K}^{\ensuremath{-}}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ final states. The are made using a dataset comprising $(772\ifmmode\pm\else\textpm\fi{}11)\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected...
Abstract We report on new flavor tagging algorithms developed to determine the quark-flavor content of bottom ( "Image missing"<!-- image only, no MathML or LaTex -->) mesons at Belle II. The provide essential inputs for measurements mixing and charge-parity violation. validate evaluate performance using hadronic --> decays with flavor-specific final states reconstructed in a data set corresponding an integrated luminosity 62.8 fb $$^{-1}$$ <mml:math...
We present the study of B[over ¯]^{0}→Σ_{c}(2455)^{0,++}π^{±}p[over ¯] decays based on 772×10^{6} BB[over events collected with Belle detector at KEKB asymmetric-energy e^{+}e^{-} collider. The Σ_{c}(2455)^{0,++} candidates are reconstructed via their decay to Λ_{c}^{+}π^{∓} and Λ_{c}^{+} pK^{-}π^{+}, pK_{S}^{0}, Λπ^{+} final states. corresponding branching fractions measured be B(B[over ¯]^{0}→Σ_{c}(2455)^{0}π^{+}p[over ¯])=(1.09±0.06±0.07)×10^{-4} ¯]^{0}→Σ_{c}(2455)^{++}π^{-}p[over...
We study the processes e^{+}e^{-}→ωχ_{bJ}(1P) (J=0, 1, or 2) using samples at center-of-mass energies sqrt[s]=10.701, 10.745, and 10.805 GeV, corresponding to 1.6, 9.8, 4.7 fb^{-1} of integrated luminosity, respectively. These data were collected with Belle II detector during special operations SuperKEKB collider above ϒ(4S) resonance. report first observation ωχ_{bJ}(1P) signals sqrt[s]=10.745 GeV. By combining results sqrt[s]=10.867 we find energy dependencies Born cross sections for...
We present the first measurement of ratio branching fractions inclusive semileptonic B-meson decays, R(X_{e/μ})=B(B→Xeν)/B(B→Xμν), a precision test electron-muon universality, using data corresponding to 189 fb^{-1} from electron-positron collisions collected with Belle II detector. In events where partner B meson is fully reconstructed, we use fits lepton momentum spectra above 1.3 GeV/c obtain R(X_{e/μ})=1.007±0.009(stat)±0.019(syst), which most precise lepton-universality its kind and...
We search for lepton-flavor-violating τ^{-}→e^{-}α and τ^{-}→μ^{-}α decays, where α is an invisible spin-0 boson. The uses electron-positron collisions at 10.58 GeV center-of-mass energy with integrated luminosity of 62.8 fb^{-1}, produced by the SuperKEKB collider collected Belle II detector. excess in lepton-energy spectrum known τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ} τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decays. report 95% confidence-level upper limits on branching-fraction ratio...
The $L_{\mu}-L_{\tau}$ extension of the standard model predicts existence a lepton-flavor-universality-violating $Z^{\prime}$ boson that couples only to heavier lepton families. We search for such $Z^\prime$ through its invisible decay in process $e^+ e^- \to \mu^+ \mu^- Z^{\prime}$. use sample electron-positron collisions at center-of-mass energy 10.58GeV collected by Belle II experiment 2019-2020, corresponding an integrated luminosity 79.7fb$^{-1}$. find no excess over expected...
We present a measurement of the τ-lepton mass using sample about 175 million e+e−→τ+τ− events collected with Belle II detector at SuperKEKB e+e− collider center-of-mass energy 10.579 GeV. This corresponds to an integrated luminosity 190 fb−1. use kinematic edge τ pseudomass distribution in decay τ−→π−π+π−ντ and measure be 1777.09±0.08±0.11 MeV/c2, where first uncertainty is statistical second systematic. result most precise date.Received 31 May 2023Accepted 13 July...
We determine the Cabibbo-Kobayashi-Maskawa matrix-element magnitude |Vcb| using B¯0→D*+ℓ−ν¯ℓ decays reconstructed in 189 fb−1 of collision data collected by Belle II experiment, located at SuperKEKB e+e− collider. Partial decay rates are reported as functions recoil parameter w and three angles separately for electron muon final states. obtain Boyd-Grinstein-Lebed Caprini-Lellouch-Neubert parametrizations, find |Vcb|BGL=(40.57±0.31±0.95±0.58)×10−3 |Vcb|CLN=(40.13±0.27±0.93±0.58)×10−3 with...