M. Bessner
A5045626962- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Particle Accelerators and Free-Electron Lasers
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- Medical Imaging Techniques and Applications
- Astrophysics and Cosmic Phenomena
- Distributed and Parallel Computing Systems
- Atomic and Subatomic Physics Research
- Scientific Computing and Data Management
- Nuclear Physics and Applications
- Advanced Data Storage Technologies
- Magnetic Field Sensors Techniques
- Advanced NMR Techniques and Applications
- Nuclear physics research studies
- Gamma-ray bursts and supernovae
- Advancements in PLL and VCO Technologies
- Structural Analysis of Composite Materials
University of Hawaiʻi at Mānoa
2019-2024
University of Hawaii System
2019-2023
University of Cincinnati
2023
Stockholm University
2020
Deutsches Elektronen-Synchrotron DESY
2014-2019
The University of Adelaide
2014-2019
Ludwig-Maximilians-Universität München
2014-2019
University of Wuppertal
2019
Brookhaven National Laboratory
2019
Hamburg Institut (Germany)
2018
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 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...
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) .
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...
Charged lepton flavor violation is forbidden in the Standard Model but possible several new physics scenarios. In many of these models, radiative decays $\tau^{\pm}\rightarrow\ell^{\pm}\gamma$ ($\ell=e,\mu$) are predicted to have a sizeable probability, making them particularly interesting channels search at various experiments. An updated via using full data Belle experiment, corresponding an integrated luminosity 988 fb$^{-1}$, reported for charged violation. No significant excess over...
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...
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.
Using data samples of 89.5 and $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ recorded at energies $\sqrt{s}=10.52$ 10.58 GeV, respectively, with the Belle detector KEKB ${e}^{+}{e}^{\ensuremath{-}}$ collider, we report measurements branching fractions semileptonic decays ${\mathrm{\ensuremath{\Xi}}}_{c}^{0}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}$ ($\ensuremath{\ell}=e$ or $\ensuremath{\mu}$)...
We present the first observation of ${\mathrm{\ensuremath{\Omega}}}_{c}^{0}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}}{\ensuremath{\mu}}^{+}{\ensuremath{\nu}}_{\ensuremath{\mu}}$ decay and measurements branching fraction ratios ${\mathrm{\ensuremath{\Omega}}}_{c}^{0}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}$ decays compared to reference mode...
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 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...
We measure the tau-to-light-lepton ratio of inclusive <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>B</a:mi></a:math>-meson branching fractions <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mrow><c:mi>R</c:mi><c:mo stretchy="false">(</c:mo><c:msub><c:mrow><c:mi>X</c:mi></c:mrow><c:mrow><c:mi>τ</c:mi><c:mo>/</c:mo><c:mo>ℓ</c:mo></c:mrow></c:msub><c:mo stretchy="false">)</c:mo></c:mrow><c:mo>≡</c:mo><c:mspace...
We describe the planned near-term and potential longer-term upgrades of Belle II detector at SuperKEKB electron-positron collider operating KEK laboratory in Tsukuba, Japan. These will allow increasingly sensitive searches for possible new physics beyond Standard Model flavor, tau, electroweak dark sector that are both complementary to competitive with LHC other experiments.