A5085529914- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- High-Energy Particle Collisions Research
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Medical Imaging Techniques and Applications
- CCD and CMOS Imaging Sensors
- Electron and X-Ray Spectroscopy Techniques
- Atomic and Subatomic Physics Research
- Black Holes and Theoretical Physics
- Particle accelerators and beam dynamics
- Scientific Computing and Data Management
- Pulsars and Gravitational Waves Research
- Graphene research and applications
- Advanced NMR Techniques and Applications
- Nuclear reactor physics and engineering
- Cold Atom Physics and Bose-Einstein Condensates
- Nuclear Physics and Applications
- Distributed and Parallel Computing Systems
- Spacecraft and Cryogenic Technologies
- Cosmology and Gravitation Theories
The University of Tokyo
2020-2024
Kavli Institute for the Physics and Mathematics of the Universe
2020-2024
Tokyo Metropolitan University
2022-2024
Institute of High Energy Physics
2019-2022
The University of Melbourne
2020
Tohoku University
2015-2019
Austrian Academy of Sciences
2019
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa
2018
University of Pisa
2018
Charles University
2018
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....
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 $\Omega_c(3090)$.
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 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.
Theories beyond the standard model often predict existence of an additional neutral boson, $Z^{\prime}$. Using data collected by Belle II experiment during 2018 at SuperKEKB collider, we perform first searches for invisible decay a $Z^{\prime}$ in process $e^+ e^- \to \mu^+ \mu^- Z^{\prime}$ and lepton-flavor-violating e^{\pm} \mu^{\mp} Z^{\prime}$. We do not find any excess events set 90\% credibility level upper limits on cross sections these processes. translate former, framework...
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 report the first observation of double strange baryon Ξ(1620)^{0} in its decay to Ξ^{-}π^{+} via Ξ_{c}^{+}→Ξ^{-}π^{+}π^{+} decays based on a 980 fb^{-1} data sample collected with Belle detector at KEKB asymmetric-energy e^{+}e^{-} collider. The mass and width are measured be 1610.4±6.0(stat)_{-4.2}^{+6.1} (syst) MeV/c^{2} 59.9±4.8(stat)_{-7.1}^{+2.8}(syst) MeV, respectively. obtain 4.0σ evidence Ξ(1690)^{0} same sample. These results shed light structure hyperon resonances strangeness S=-2.
Abstract From April to July 2018, a data sample at the peak energy of resonance was collected with Belle II detector SuperKEKB electron-positron collider. This is first experiment. Using Bhabha and digamma events, we measure integrated luminosity be ( , where uncertainty statistical second systematic. work provides basis for future measurements II.
We present measurements of the first to fourth moments lepton mass squared q2 B→Xcℓ¯νℓ decays for ℓ=e, μ and with Xc a hadronic system containing charm quark. These results use sample electron-positron collisions at Υ(4S) resonance corresponding 62.8 fb−1 integrated luminosity collected by Belle II 2 experiment in 2019 2020. To identify reconstruct q2, one B mesons from an Υ(4S)→B¯B decay is fully reconstructed mode using multivariate tagging algorithm. report raw central q2>1.5 GeV2/c4 up...
This paper presents a search for the rare flavor-changing neutral current process ${B}^{0}\ensuremath{\rightarrow}{K}^{*0}{\ensuremath{\tau}}^{+}{\ensuremath{\tau}}^{\ensuremath{-}}$ using data taken with Belle detector at KEKB asymmetric energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. The analysis is based on entire $\mathrm{\ensuremath{\Upsilon}}(4S)$ resonance sample of $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, corresponding to...
We present the measurement of absolute branching fractions ${B}^{+}\ensuremath{\rightarrow}{X}_{c\overline{c}}{K}^{+}$ and ${B}^{+}\ensuremath{\rightarrow}{\overline{D}}^{(*)0}{\ensuremath{\pi}}^{+}$ decays, using a data sample $772\ifmmode\times\else\texttimes\fi{}{10}^{6}\text{ }\text{ }B\overline{B}$ pairs collected at $\mathrm{\ensuremath{\Upsilon}}(4S)$ resonance with Belle detector KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. Here, ${X}_{c\overline{c}}$ denotes...
We report the first evidence for isospin violation in $B\ensuremath{\rightarrow}{K}^{*}\ensuremath{\gamma}$ and measurement of difference $CP$ asymmetries between ${B}^{+}\ensuremath{\rightarrow}{K}^{*+}\ensuremath{\gamma}$ ${B}^{0}\ensuremath{\rightarrow}{K}^{*0}\ensuremath{\gamma}$. This analysis is based on data sample containing $772\ifmmode\times\else\texttimes\fi{}{10}^{6}B\overline{B}$ pairs that was collected with Belle detector at KEKB energy-asymmetric ${e}^{+}{e}^{\ensuremath{-}}$...
We search for a new gauge boson $Z'$ that couples only to heavy leptons and their corresponding neutrinos in the process $e^{+} e^{-} \rightarrow Z'(\rightarrow \mu^{+}\mu^{-}) \mu^{+}\mu^{-}$, using 643 fb$^{-1}$ data sample collected by Belle experiment at or near $\Upsilon(1S,2S,3S,4S,5S)$ resonances KEKB collider. For first time, effects due initial state radiation are used estimating detection efficiency. No signal is observed mass range of 0.212 \ -- 10 GeV/${\it c}^2$ we set an upper...
We report the results of a search for rare, purely leptonic decay B^{-}→μ^{-}ν[over ¯]_{μ} performed with 711 fb^{-1} data sample that contains 772×10^{6} BB[over ¯] pairs, collected near ϒ(4S) resonance Belle detector at KEKB asymmetric-energy e^{+}e^{-} collider. The signal events are selected based on presence high momentum muon and topology rest event showing properties generic B-meson decay, as well missing energy being consistent hypothesis neutrino from decay. find 2.4 standard...
We report a new measurement of the exclusive ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{(*)\ifmmode\pm\else\textpm\fi{}}{D}^{*\ensuremath{\mp}}$ cross sections as function center-of-mass energy from ${D}^{(*)\ifmmode\pm\else\textpm\fi{}}{D}^{*\ensuremath{\mp}}$ threshold through $\sqrt{s}=6.0\text{ }\text{ }\mathrm{GeV}$, using initial-state radiation technique. The analysis is based on data sample collected with Belle detector an integrated luminosity $951\text{...
The photon energy dependence of angle-resolved photoemission spectroscopy (ARPES) in graphene is investigated experimentally and theoretically. By applying light with around $46\phantom{\rule{0.28em}{0ex}}\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$, we found an unexpected increase the ARPES relative intensity for $p$ branch (ARPES spectra brightened by $p$-polarized light) respect to $s$ (those $s$-polarized light). origin enhanced $p$-branch explained first-principles calculations, which show...
We study bottomonium production in association with an $$\eta $$ meson $$e^+e^-$$ annihilations near the $$\varUpsilon (5S)$$ , at a centre-of-mass energy of $$\sqrt{s}=10.866$$ GeV. The results are based on 121.4 fb $$^{-1}$$ data sample collected by Belle experiment asymmetric-energy KEKB collider. Only is reconstructed and missing-mass spectrum candidates investigated. observe $$e^+e^-\rightarrow \eta \varUpsilon _J(1D)$$ process find evidence for (2S)$$ process, while no significant...
The first measurements of differential branching fractions inclusive semileptonic B→X_{u}ℓ^{+}ν_{ℓ} decays are performed using the full Belle data set 711 fb^{-1} integrated luminosity at ϒ(4S) resonance and for ℓ=e, μ. With availability these measurements, new avenues future shape-function model-independent determinations Cabibbo-Kobayashi-Maskawa matrix element |V_{ub}| can be pursued to gain insights in existing tension with respect exclusive determinations. reported as a function lepton...
We present a measurement of the Michel parameters $τ$ lepton, $\barη$ and $ξκ$, in radiative leptonic decay $τ^- \rightarrow \ell^- ν_τ \barν_{\ell} γ$ using 711~f$\mathrm{b}^{-1}$ collision data collected with Belle detector at KEKB $e^+e^-$ collider. The are measured an unbinned maximum likelihood fit to kinematic distribution $e^+e^-\rightarrowτ^+τ^-\rightarrow (π^+π^0 \barν_τ)(\ell^-ν_τ\barν_{\ell}γ)$ $(\ell=e$ or $μ)$. values $\barη = -1.3 \pm 1.5 0.8$ $ξκ= 0.5 0.4 0.2$, where first...
Using a data sample of $980\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ ${e}^{+}{e}^{\ensuremath{-}}$ annihilation taken with the Belle detector operating at KEKB asymmetric-energy collider, we report results study decays ${\mathrm{\ensuremath{\Omega}}}_{c}^{0}$ charmed baryon into hadronic final states. We most precise measurements to date relative branching fractions ${\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{0}$,...
The enhancement of charged-particle pairs with large pseudorapidity difference and small azimuthal angle difference, often referred to as the ``ridge signal'', is a phenomenon widely observed in high multiplicity proton-proton, proton-ion deutron-ion collisions, which not yet fully understood. In heavy-ion hydrodynamic expansion Quark-Gluon Plasma one possible explanations origin ridge signal. Measurements $e^+e^-$ collision system, without complexities introduced by hadron structure initial...
We report a measurement of the D^{0} and D^{+} lifetimes using D^{0}→K^{-}π^{+} D^{+}→K^{-}π^{+}π^{+} decays reconstructed in e^{+}e^{-}→cc[over ¯] data recorded by Belle II experiment at SuperKEKB asymmetric-energy e^{+}e^{-} collider. The data, collected center-of-mass energies or near ϒ(4S) resonance, correspond to an integrated luminosity 72 fb^{-1}. results, τ(D^{0})=410.5±1.1(stat)±0.8(syst) fs τ(D^{+})=1030.4±4.7(stat)±3.1(syst) fs, are most precise date consistent with previous...